It's a carpet stretcher and laying tool. The blade is for smoothing and tucking carpet under door-sills, skirting boards and such, the multiple spikes are for gripping the carpet while it is stretched, the cup is for holding tacks, and the long spike would have fitted into a wooden handle. There's a patent for a very similar item here:
This is the one pictured in that old patent. The blade has a semi-circular notch, which I think would be useful for fitting carpets around pipework (although the patent says it's to assist the nailing of tacks). Yours is another and more modern variation, but you get the idea?
AT Pro, AT Max, AT Gold - Tesoro Euro Sabre - Tesoro Bandido II uMax - Troy X2 - Tesoro Stingray - Mojave - Fisher 1280X- Fisher 1235X - and many more.
I'm going with the meat tenderizer guess. There are many different types that have a chopper blade. Is there a hole next to your thumb in the picture? I wonder if that would be for a wooden handle.