Kids table and buffet style?

I'm sure the kids wouldn't go up on their own and their parents will help and assist them. I don't see it being an issue.

It depends on what's in the buffet and whether it's self served. A lot of places are opting to have their staff serve the portion of food rather than have guests scoop it themselves so that should alleviate some mess.

I don't know if you want to designate the teenagers as babysitters for the younger ones but they would be old enough to watch them. They might also not have the patience for any shenanigans the young ones pull off though.

I think it's a great idea!

I dont think it would be a problem. We had family style and a kids table. One parent went to the table during each course to help kids set up. The ones closer to 5-7 may need a parent to get them set up but once they are seated it'll be fine. The older ones should be ok. However, you know the kids better than I do. We had 9 kids at a table with parents beside them at next table.