Keynote
You can change the look of text for the entire table or just for specific table cells.
Go to the Keynote app on your Mac.
Open a presentation with a table, then do any of the following:
To change all the text in the table: Select the table.
To change the text in specific cells: Select the cells.
In the Format sidebar, click the Text tab.
Click the Style button, then use the text controls in the font section to change the font, size, colour or character style (such as bold or italic).
Note: To apply a character style from the Character Style pop-up menu, select just the text you want to change. You can’t select a style from this menu if a cell, row, column or the entire table are selected.
You can increase or decrease the font size proportionally for all text in the table.
Go to the Keynote app on your Mac.
Open a presentation with a table, then click the table.
In the Format sidebar, click the Table tab, then click the Table Font Size buttons.