Hello and welcome!
Personally, I'd sit the kids with their parents. They'll be supervised and under much better behavior than if they were all sitting together.
If you do decide to sit them together it sounds like you'd need a couple tables. Be sure to have an adult or teen sit at the table with the kids (this is not so fun for them :( ) to keep an eye on the kids and make sure no one gets out of hand.
Good luck!
Melissa