Excel Table Format

I have a spreadsheet with multiple tables (they're not actually formatted as tables but as charts) that are listed one after another. I would like each table to alteate in color. I would also like it to be set so that if I add or remove an entire chart the coloring scheme updates automatically. I'm attempting to use conditional formatting but I can't get it to alteate for every table. I thought if I merge the table to act as one cell that would work but I can't get it to do that. Any thoughts?