I found this table on the curb a while back, less the leg hardware. No a relative could use it, and I'm wondering how to fix it up.

Cut a couple 2x4 sections to fill the truncated-triangular area and screw through them into all surfaces?

The legs have a hollow center drilled out, at the top, so I assume some metal piece with threaded holes fit there, and a metal plate anchored that to the skirt (?).

Another view: