Perhaps the thing to do is for the LSA to get some idea of passengers' preferences (at least for dinner and also for lunch when lunch reservations are required) when they take the meal reservations. They could note the preferences on their reservation sheets under at least three categories such as:
Roomies (who prefer to eat in their room)
Recluses (who prefer their own table in the dining room - no strangers)
Party Animals (who prefer to dine with others, including strangers)
The LSA can then determine how to space the reservations. For example, if there are 20 Recluses who all want to dine at 6 p.m., the LSA will realize that they cannot all be accommodated at the same time and will have to assign different times to some. If a Recluse occupies a table for more than an adequate time to dine, the LSA can assign another Recluse or some Party Animals to join the first Recluse which may spur the first Recluse to finish and leave.
Passengers could also be distributed colored badges depending on their preference. So if the LSA sees a passenger enter the dining room wearing a red badge, the LSA will realize instantly that that person is a Recluse and should not be seated with others. If they are wearing a blue badge, the LSA will recognize that person as a Party Animal and will seat them with other Party Animals but not with a Recluse. And if they are wearing a green badge the LSA will realize that that person is a Roomie who doesn't want to eat in the dining room at all.