Yes. Either email, rccldining@rccl.com (though not sure of that email) or call c&a, either you your ta, and request that everyone is linked for dinner. You'll need everyone's reservation #, and names as on reservation. Saying this I would still expect you still might to check with maitre d after boarding and you have your seapass cards. Hopefully you'll find everyone assigned to same table. If not get on line.