Clamp Overlap cancels Bevel effect

The problem is some duplicate vertices - 9 to be exact. Go to edit mode, select all, and select Mesh > Merge By Distance. A little window will pop up in the bottom left corner. Click to expand the little box, and press the arrow on the right side once until the value is 0.0101. They will be removed and the bevel will work cleanly.

EDIT - I'm glad the fix worked for you, but after playing with the object some more afterwards, I noticed some anomalies in the topology. Just in case, I have attached a simple .blend file with a similar table in 2 forms - The first has the original topology I used to make the table, and the second one I removed "unnecessary" (for game engines) edges, so it is reduced as far as possible with the possible exception that I did not delete the bottom faces. Both have the same bevel modifier with the default settings. Maybe use them as a reference or comparison to see what differs between the topology of the 2 of them, and yours.

File is here -

Cheers