As a professional poker player I know what works and what does't involving poker tables. One of the most common complaints I hear while playing are related to them. How hard it is to look at the cards, maneuver poker chips, not enough player space & other more serious potential catastrophes. When considering size the most important factor is its going to be how many players will be seated.
Keep in mind poker games often run for long lengths of time. Plus people want to be constantly in the action & do not get up to take breaks often. This means it needs to offer more than a typical one would that is used for brief time periods. The more comfortable a player is the longer they will stay.
Space is also an issue. If you have a dedicated area then don't worry about this. But if you are going to be hosting the game in the kitchen you can use a foldout style or table top/cover. It will fit right on top. And both will fit nicely in a closet while not playing. These options are especially good for saving space and hassle. And especially good for those on a budget.
One of the most important things to consider is you do not want someone bumping into it and spilling the chips all over the floor. Forget the mess! Worry about it being a disaster for the game! Poker chips are used to keep track of who is winning or losing and this would cause a big problem to have them mixed up & scattered everywhere. Another downfall to these styles are they only fit six players. And can be a little clumsy even if nobody bumps it if too cheap of one is purchased. The following suppliers are whom I recommend for reputation & selection.