I would say no. All you need to do is have your TA put in a request for a table for 2- most cruise lines will honor your request if you get it in early enough, they will even make a fuss ( if you want them to) on your actual anniversary date, cake and stuff like that. The only time i would tip for a table would be if you needed to be moved and you made this a special request directly to the Maitre'D
Most ships do have tables for two, but they are limited. As mentioned, ask your TA to make that request. If it is not fulfilled, go to the Maitre' de's station once on board and see if they can do anything for you. Then a tip should be extended.