When you add a table, you can choose from a number of styles designed to match your theme. After you add a table, you can customize its appearance.
Click Table 
in the toolbar, then select a table layout.
Click the left and right arrows to see more style options.
To type in a cell, click the cell, then enter your content.
To move the table, click it, then drag 
in the top-left corner to move it to where you want it on the slide.
To change the appearance of a table or its cells, use the tools in the Table, Cell, Text, or Arrange panes of the Format inspector.
Click the table, click in its top-left corner to select the whole table, then press Delete.
Tables have a placeholder name, such as “Table 1,” that you can show, edit, or hide. Each table must have a unique name in the presentation.
Do any of the following:
Show or hide a table name: Control-click the bar to the left of row 1, then choose Show Table Name or Hide Table Name.
You can also select or deselect the Table Name checkbox in the Table pane of the Format inspector.
Change the name: Triple-click the name on the slide, then type a new name.
Enclose the table name in a border: Select the “Outline table name” checkbox in the Table pane of the Format inspector.