The 68020 was usually mated to the 68881. I'm not sure if they can be interchanged or not. The card is probably for the LC II and III/III+ (or maybe just the III/III+ if the connector has the extra pins).

I do have a 68882 card for my Classic II, and it is indeed tiny. (The FastMath Classic II card, as it is known, plugs into that rarely-used expansion slot on the logic board of the Classic II).