I would start with 15 tables/chairs in each section. Then watch for broken hearts if u don't see any u might be able to take 1 table & chair from each section. Play around with this. The key is to have minimal walking distance from the door to the last seat. In my picture just a few post b4 this one u will see the maximum walking distance is 5 steps. So play around with the shape of each section u might do better with straight rows or with the t-design.