You can change the look of a table by changing the table outline, showing or hiding gridlines, and using alternating row colors.
Tap the table, then tap 
.
Tap Table, then do any of the following:
Show the outline: Turn on Table Outline.
Change the gridlines: Tap Grid Options, then tap to turn gridlines on or off.
If you don’t see these options, swipe up from the bottom of the controls.
You can change the border and background of any selection of table cells.
Select the cells you want to change.
Tap , tap Cell, then do any of the following:
Change the border: Tap Border Style, then tap the border you want.
Change the background: Tap Cell Fill, then tap a color. Swipe left and right for more color options.
Tap the table, then tap .
Tap Table, then turn on Alternating Rows.
Row colors don’t alternate for header columns. Header columns have their own look based on the table style you choose.