J.G.
We have done this with my dad's family. He is one of 7 children so it is quite a group. Each sibling/ group of siblings (depends on the size of their families) to plan the meals for that day. They all contribute money and give their shopping list basically one person goes shopping at Sam's. Some of the family live where we havd had the reunion so that makes it easy for them. I would say for families to pick a meal and plan it and buy the groceries for that meal for everyone. You may still have expenses for paper products, silverware, drinks, etc. Each family could bring supply their own.