A pretty good indicator of the amp rating is the size of the fuse on the circuit the relay is controlling. The micro relays are probably 20 amp max rated,seeing most of the ones on GM cars and light trucks are fused with a 20 amp fuse or less, while the full size bosch style can be 30 amp or 40 amp, some of those have HUGE spades for terminal 30 and 87 87a, they could be rated at 50 or more.
As far as exact specs, IDK , deductive reasoning can be a good aproach to making a good educated guess.
Those full size relays in the picture with the puny little spade connectors may not be very heavy duty. I would be suprised if they are more than 20 amp rated, I could be wrong.