Looks like a meat tenderiser an oar and some other stuff.
You're right about the meat tenderizer (modified with a 3" radius cut into the head) and the "oar" is just a 1.5" dowel for a test run...
But this tool has a name, and a long, long, long history
. What is it called, and what was its original use? While it's original use is rare today, it is still used for marlin spike fancy work and other wraps.
Just a brain teaser... no fair using google-fu
Why, that's a seizing mallet!
Ding, ding, ding.... We have a winner!
Also called a serving mallet, its original use was to apply the serving (outer marline wrap) to the standing rigging
on the windjammers. Worm and Parcel with the lay, turn and Serve the other way.