There can be some very huge differences, depending on what kind of tables you are playing on. We recently had to travel to a room with Valley bar tables (our room is all Brunswick 9 footers) and there was immediately a problem with the oversize cue ball. This ball requires you to adjust your aiming on all cut shots, because the oversize ball changes the actual contact point when you aim your shot. Another problem can be with a heavier cue ball which will be harder to control your draw.
You didn't say if you play 8 ball or 9 ball, but smaller tables will often hit you with another problem....more clusters. A 9 foot table has about 36 sq feet of playing surface...a 7 footer has about 25 sq feet. That is HUGE!!! There is much less room for all those balls on the smaller tables, so they tend to be a lot closer to each other.
People seem to think that a smaller table is automatically easier, but if you aren't ready for them, they can drive you nuts. If you play a lot of league matches on the bar tables, you probably want to get some practice time in on them.
There is a lot to adjust to when you move from one size table to another.
Steve