As a previous poster said, call and have them put the request on your reservation. If you don't want to wait until dinner time to find out if your request was granted, you can check as soon as you get on board. Check the Navigator to see where they are taking dining assignment changes. They can tell you whether or not you are seated alone. They might - emphasis on might - be able to change it at that time, but only if they have availability. I've always read on here that being in the second seating helps. I know on our last cruise there were a lot of empty tables at second seating.