The cruise lines do try to match people up as much as possible for dining room assignments. Families with other families, singles together, grouping by age, etc. They used to ask your profession and other questions to further identify those who might be compatible dining mates, but people apparently objected to the questions. But, they don't know much about us so they don't always get it right. Plus, last minute bookings, etc., can totally throw a wrench in their planned assignments. That's why you don't have any guarantee even on dining times until you get on board.