Have one like this. Looks like a wooden tenon punch. Better than the one I have.
It is a self centering drill guide. I am building a 2 1/2" thick Walnut live edge dining room table.
The wood is so heavy I have to be able to take it apart to move it around. I just finished up for the night.
There will be four 3/8" x 4" hardened steel alignment pins to keep the two halves together. This needs VERY precise measuring, marking and drilling. You can't be off by even half a mm or it wont fit correctly.
The pins fit very tightly so there is no wiggle room. After drilling all 8 holes and puckering up they all fit.
Then I pulled them apart and JB welded the pins into one side.
The round things are Zip Bolts. They are what hold the two halves together. The brass looking screws are nutcerts. They will hold the steel legs in place.