This is a simple solution for a collapsible/removable table in a camper van. The socket for a removable leg is designed to take a 19x45mm square profile leg - standard size in any building supply shop on this side of the world. When table is not needed, simply pull the leg out of the socket and either remove the table or let it hang. As pictured, it is used together with a couple of clips to secure against the 12mm steel rod on the opposite side (really a cupboard handle which features a 12mm straight rod). For clips see my other design: https://www.thingiverse.com/thing:4790550

NOTE: the design features a flat area on the bottom side, meant to be used to stick a noise damping material, like self-adhesive felt patches for furniture. You might want to use it, depending how you resolve securing the table which hangs in unused, collapsed state, and moves as you drive, hitting the the piece it hangs on...