We have found that the bigger the table, the better the chances of having a good time. Sharing a table with a strange couple is chancy but we have had good luck. The odds of them not taking a shine to us is about the same as our not clicking with them.
We try for table for eight or just the two of us.
What really irks me is the attitude that "I am on vacation" and all rules of civility and concern for others is put on hold. Those are the true "jerks". Showing up for dinner in the same tank top that you have been sweating in all day saying you would normally shave and shower but "I'm on vacation". I once asked a fellow if his hellions always acted like that and he said of course not but they were on vacation and should have fun. If the fun is at my expense, it usually gets ugly, which I suppose makes me the cause of other's distress.
Another attitude on cruise is the blue noses that let you know that they usually travel in higher stratas but got booked on this one unknowningly or just to see what it is like. Then they let everyone know how this experience doesn't measure to what they are used to. When I get tired of it, which doesn't take long, things get ugly, which I suppose gives them more to complain about.
Then there is the guy who berates the service staff, insists on special attention, refuses to wait his turn, and makes sure that everyone gets out of the way of his family because he paid $5000 and is going to get his money's worth. I won't get out of his way, things get ugly, which I suppose reinforces his contention of why dealing with the common herd takes his positive attention.
It's been my observation that the more insecure people are, either with their situation or themselves, the more people tend to hold court. Conversation is low key, in response to other's interests and really does involve moments of silence.
It is nice to see the look of relief on our table mate's faces which means they were as concerned as we were about who they were going to have to put up with.