shana, neither the Vista or the Penthouse suite has a dining room table in the cabin. Both have round tables and four chairs, and two loungers on their balconies. You have to move up to the Grand Suite to get a dining room table.
All the Penthouse Suites are on Caribe Deck, midship. This is a good location, but your Vista Suite aft will be much quieter; there will be much less foot traffic past your door. And as I said in a previous post, the aft balconies are much preferable to the side balconies.
Again, I think you should stay in your Vista Suite.