Some suggestions:
1. Maybe she needs some exercise. That would get rid of the fat and make her need to jump around less. Can you allow her out in the yard? Or take her for walks?
2. That probably isn't why she liks being up on table and counters, though. To discipline her, when she's up there go pick her up, say NO loudly and put her in a cat carrier for a time. 20 minutes? Whatever you tihkn works. Do this consistently and she'll learn that you don't want her up there. Whether she'll abide by that when you're not there is another thing.
3. Post this question on a pets forum for much better answers - though this one has so many cat owners you ought to get some great ideas here.