Table Corner Guard

Use flexible TPU or any other rubber like material.

I designed this table corner protector so it protects from bottom and top bumps and stays in place.
Adjust z-height of print as needed for you table thickness.
Add adhesive tape to top and bottom, attach to table by pressing parts together.
For me its a tight fit that needs no glue. Maybe you need to adjust bottom part by +/- % with your printer and chosen material.