Keynote
Change the table font, size, style, or color in Keynote for iCloud
You can change the font, size, style, or color of all the text in a table at the same time, or of only selected cells. You can also increase or decrease the font size proportionally for all text in the table.
Change the font, size, style, and color of table text
Click the table.
Do either of the following:
Change the look of all text simultaneously: To select all the table cells, press Command-A (on a Mac) or Control-A (on a Windows computer).
Change the look of text in a cell or range of cells: Select rows or columns.
Click Cell at the top of the Format sidebar on the right, then below Font, make your choices.
Change the size of all table text proportionally
Click the table.
Click Table at the top of the Format sidebar on the right, then click the Table Font Size buttons until you reach the desired size.