Thinking back on our cruises, our only really bad experiences in the dining room were during open seating meals like breakfast or lunch when you walk in and they stick you at a table. They don't talk, they tell, and I get tired of being told. If the table is large, the others make it so obvious the bore isn't appreciated, but it seems to go over their heads.
Assigned seating, on the other hand, usually works out fine. Have to admit, after two politically charged careers, I enjoy dining alone with my wife of 43 years.