You can add content to a table in several ways. You can type new content directly into cells, copy and paste content from somewhere else, or let Numbers complete patterns for you with autofill. You can always edit or clear a cell after you add content to it.
Note: If you can’t modify a table, make sure it’s unlocked. Click the table, then choose Arrange > Unlock (from the Arrange menu at the top of your screen).
Do any of the following:
Add content to an empty cell: Click the cell, then start typing.
As you type, Numbers shows a list of autocomplete suggestions. This list includes any text previously entered in that column, excluding header or footer text. Press the Tab key to scroll through the list. When the suggestion you want is selected, press the Return key to enter it in the cell. You can turn autocomplete suggestions off or on in Numbers preferences.
To insert a line break in a cell, press Option-Return.
Paste multiple paragraphs into a single cell: Copy the paragraphs you want to paste, double-click the cell, then choose Edit > Paste from the Edit menu at the top of the screen.
Edit content: Double-click a cell to make the insertion point appear, then type. To move the insertion point, click where you want it, then type.
Replace content: Click the cell, then start typing. The existing content is overwritten.
Delete all content: Click the cell, then press Delete on your keyboard.
See Format cells to display different types of data to learn how to set specific data formats for cells.
You can also Add an object to a cell and insert a link in a cell.
You can paste objects—including images, lines, shapes, and text boxes—into table cells. You can also add text to a cell that already has an object.
Select an object (image, line, shape, or text box) in your spreadsheet (or some other document), then choose Edit > Cut or Edit > Copy (cut removes it from its original location).
Click the cell where you want to add the object. (You can paste the object into a cell that already has text.)
Choose Edit > Paste.
By default, Numbers scales the object to fit in the cell. To change the object’s size, click the Cell tab at the top of the sidebar on the right, click the disclosure triangle next to Fill, then click the “Scale to Fit” pop-up menu and choose another option.
If you don’t see a sidebar, or the sidebar doesn’t have a Cell tab, click 
in the toolbar.
To remove an object from a cell, click the cell, click the Cell tab at the top of the sidebar on the right, click the disclosure triangle next to Fill, then click the Image Fill pop-up menu and choose No Fill.
You can quickly fill cells, or a row or column, with the same formula, data, or a logical sequence of data—for example, a series of numbers, letters, or dates.
Do any of the following:
Autofill one or more cells with content from adjacent cells: Select the cells with the content you want to copy, then move the pointer over a border of the selection until a yellow autofill handle appears. Drag the handle over the cells where you want to add the content.
Any data, cell format, formula, or fill associated with the selected cells is added, but comments aren’t. Autofilling overwrites existing data with the content you’re adding.
Autofill cells with sequential content or patterns from adjacent cells: Type the first two items of the series in the first two body cells (not header or footer cells) of the row or column you want to fill; for example, type A and B. Select these cells, move the pointer over a border of the selection until a yellow autofill handle (a dot) appears, then drag the handle over the cells you want to fill.
You can also autofill cells using a pattern of values. For example, if two selected cells contain 1 and 4, the values 7 and 10 are added when you drag over the adjacent two cells (values are incremented by 3).
Autofilling doesn’t establish an ongoing relationship among cells in the group. After autofilling, you can change the cells independently of each other.
When you autofill cells, any formulas that refer to those cells are updated automatically to use the new value.
When you copy a cell, or move a cell’s data to a new location in the table, the cell’s properties are also copied or moved, including its data format, fill, border, and comments.
Select the cells you want to copy or move.
Do one of the following:
Move the data: After selecting the cells, click and hold the cells until they appear to rise off the table, then drag them to another location in the table. Existing data is replaced by the new data.
Paste and overwrite existing content: Choose Edit > Copy (from the Edit menu at the top of your screen). Select the top-left cell where you want to paste the data (or select an area of the same dimensions as the cells you’re pasting), then choose Edit > Paste.
If your data range contains formulas but you want to paste only the results, choose Paste Formula Results.
Paste without overwriting: Choose Edit > Copy, select the destination cells, then choose Insert > Copied Rows or Insert > Copied Columns (from the Insert menu at the top of your screen). New rows or columns are added for the copied cells.
Paste a cell style: Choose Format > Copy Style (from the Format menu at the top of your screen), select the cells where you want to copy the style, then choose Format > Paste Style.
Paste cell contents without the style: Choose Edit > Copy, select the cells where you want to paste, then choose Edit > Paste and Match Style. The pasted cells adopt the formatting of the new location.
Paste outside of an existing table to create a new table: Drag the cells outside the table. A new table is created with the pasted cells.
If you copy a range of cells that include hidden data (either hidden or filtered), the hidden data is also copied. If you paste to a range of cells with a matching arrangement of hidden cells, the hidden data is also pasted. Otherwise, the hidden content isn’t pasted.
As you type in a cell, Numbers can show a list of autocomplete suggestions. This list includes any text previously entered in that column, but not header or footer text. Autocomplete is on by default, but you can turn it off or on at any time.
Choose Numbers > Preferences (from the Numbers menu at the top of your screen).
Click General at the top of the preferences window.
In the Editing section, select or deselect “Show suggestions when editing table cells.”
You can temporarily highlight a cell’s row and column in blue as you move the pointer over a table. In a large table, this can help you identify column and row references for specific cells.
Hold down the Option key while you move the pointer over a cell.