No, it is not hard to have your seating changed. If you are unhappy, just see the maitre 'd and tell him you want another table. After all, you are on your cruise to have a good time. And don't be shy about it. It happens all the time. I've done so myself on several occasions for a variety of reasons. This might even be one of the motivations for several ships having changed to "free style cruising," which does away with both assigned seating and having to eat at a certain time or in a specified dining room.
A note of interest, once I was on a two week cruise and noticed the second week that a man was dining by himself at a small table in a remote corner of the dining room. I commented to my waiter that the passenger must be a real loner. The waiter explained that was not the case at all. The passenger had been so obnoxious at the first table he was assigned at the beginning of the cruise that everyone there asked to move. He was placed at another table, and the same thing happened, and, again, for the third time. After that, the maitre 'd gave him a table to himself, because word had spread and no one wanted to be seated with him.
I found the dining situation on Celebrity to be a source of stress for me as a single person. If I cruise again I plan to go either on a line that has freestyle or on a smaller, more informal ship.
Let me say first that Celebrity's food was OUTSTANDING. I have never had gourmet food like that in my life and certainly not for a full week straight. Menu is under the supervision of a famous French chef.
The other side of the coin: The dinner seatings are large (each seating can hold over 800, though the ship was quite a bit under capacity that week). I wanted my seating changed two times -- once from late to early sitting and once to change table. The "maitre d" didn't handle it well either time. Didn't seem knowledgeable about the different tables (well, I guess it is a large facility) or particularly helpful; more like this was a hassle. He was really quite abrupt. As for the table change, he just looked at a chart of numbers and found one that was under capacity (it turned out to be three couples, nice people, but come on!)
Partly I wondered if it was cultural (without getting into specifics, he wasn't American; but I must add I had some lovely wait staff who were not American either).
They just couldn't seem to deal well or sensitively with the situation.
You can request "casual alternative" any night but you have to make a reservation in the afternoon and I don't know if they get all the same gourmet food.
If you aren't placed at a table you like, you can always "cruise" (no pun intended) around the room and check out vacant seats. If the group there seems like they're having fun, and you feel you would enjoy their company, just ask if you can join them if there's room. Don't blink an eye at being bold if it means having a more enjoyable cruise. After all, it is YOUR vacation!
Last summer I went solo on the Carnival Victory Ship and the first night I was at a table for four people( late seating) and I was the only one to show up at the table; I spoke with the Maitre De and was changed to another dining room (late seating) and two families of three people each and I had a ball.
You definetly can change your table....I liked my table mates from the second night to the last....Kar-