I'm willing to bet you're missing a nylon glide or 2 from the bottom of the legs. You can purchase replacements from any home improvement store. (like Menards or Home Depot.)
Hi Gerogette, sorry you are having problems with your kitchen table. Hope this is helpful. Good luck How to Level Furniture on a Sloped Floor | Hunker
This might not seem like a big deal until you place a furniture piece on the floor and watch it wobble on its uneven base. If your floors are slanted, you can level the furniture in your home in several different ways. ... Adjust the legs to level the furniture against the floor.
Tighten all screws, nuts, and bolts.
If it is wooden table you may need to shove some tooth picks into the screw holes to help the screws stay tight. If it is a metal based table you may need to look at the welds to make sure they are still strong. But whatever it is look for the fasteners and tighten them first, then make it level.
Go under it and tighten the screws in the legs