You can make reservations for large groups in any of the main resturants. Stop by on the first day and let them know what nights you wish to eat as a group. You will need to eat at none peak times. Normally they provide you a choice of 5:30 or 8:30 in order to be able to hanndle the freestyle peak from 7-8 pm.
With all the choices you may find the group wanting to break up into smaller groups and eating in different resturants. If you decide not to use your reservation all they ask is for you to let them know.