PS is Pferdestärke, which is just horsepower in German. I think CH is the same in French, and CV... Italian? So maybe the other ones also all mean HP. I don't know why they put all of them there, but maybe it's because since it's not a SI unit, there is no official abbreviation everyone knows.
Edit: Just looked it up and I was wrong, they are actually different units, even though horse related. Even HP (747.7 W) and PS (735.5 W) are slightly different. What a mess, that's why we need SI units.
Well, I just ended up looking up horse power. So there's metric horse power, mechanical horse power, brake horse power. Most of the ones in your picture are some kind of horse power.