They can do it. We had a table for 12 on the Island, the sistership of the Coral, a little while back. We were just the 2 of us but when we found out there were 5 couples on board from the country we were born (Holland) we asked if we could get a table large enough for the 12 of us. Answer; No problem and we dined together several times in the main dining room. Maybe it did help that the Food & Beverage manager was also from Holland 😉.
Like others stated above, ask the Maitre'D or the headwaiter when you board although don't count on the first night.