On the Magic and Wonder the max per serving station is 18 people - whatever the seating arrangement. More than that and the servers can't get things out in a timely fashion.
On our last cruise we had 32 DISers. The head waiter was able to move things around so that we were in two stations, one right next to each other. We were told that there had to be at least one adult at the kids table but no one said anything when all of the adults left the kids "alone" (ok, at the next able)
Moral to the story: call DCL and put in your request and then get everyone together when you have your KTTW cards and make sure you are all on the same rotation. Linking reservations does not guarantee you will be on the same rotation (you'd think so - but on the last two cruises we were not )