Having sailed recently on the QM, I think the assumption that the other diners would be over 60 is wrong, especially in the Britannia Restaurant. The 'older' set is more likely to be found in the Grill restaurants. I know, I was one of them at 60. But then, this is the crowd with whom I have much more in common. And a table for 2 has neighbors and one can always chat with them if the spouse gets boring or sleepy.

Jane in PHL (sailing for sailing's set on the Seabourn Line)