Unsure of which model trailer you have, so this is speculation. Most dinettes are manufactured outside the RV, then installed and screwed to the floor/walls. Removing them is usually just a matter of finding all the screws, being careful with the removal and careful removal through the RV door.
The biggest challenge will probably be dealing with the compressed carpet under the dinette.
If you install a pedestal table, be careful not to screw through the slide floor as the point on "too long screws" can tear the carpet/vinyl when the slide comes in. If your dining area is not in a slide, be careful because there may be a tank, a ROMEX run, a water line or a heat duct directly under the floor. Screws driven too deeply can penetrate any of those structures.....
2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS