Hi,
For all I can observe, looking at the pictures, the little serrated plates are certainly not hand-made but cut out by a machine. IF they are aluminium (which I doubt), the serrations cannot be meant to be pushed or hammered into any hard wood, the aluminium being too soft for that.
IF these are were indeed meant to prevent a piece of wood of moving in regard to another, there would not be many ways to attach them to the piece of wood holding them before "use".
One possibility I am thinking of is that the little plate would be screwed to piece wood "A", with only the serrated part protruding over the edge. Since the wood screws are about 25 mm long, piece of wood "A" would have to be at least 30 mm thick. I am thinking of a thick plank here.
The second hole in the "plank" wold then also receive a screw or a nail to prevent the little plate to pivot around the screw.
The piece of wood "B" that had would have to have the serrations "bite" into, would have to be applied perpendicularly to the axis of piece "A". This makes me think of "B" closing onto "A" as a hinged lid would do. After which the lid may have been nailed shut.
So, I am thinking of a box made of fairly light and soft wood, not a table or anything.
Another thought is that the little plates are of inexpensive manufacture, cheap, mass-produced, as for a disposable box. That makes me think of a wooden ammunition box: light and expendable. The lid may have had to be held firmly in place until opened for e.g. reasons of waterproofing by means od some sort of seal or so.
The bent plate was bent by mechanical action, probably when breaking the box open for one reason or another (firewood?). The bend is certainly not of manufacturing origin.
Just my two cents' worth.
Rudolf.