As I read it, when current closes A & B, terminals 1+4+7 close, terminals 2+5+8 close and terminals 3+6+9 close. Simple enough.
You're right about the current rating, more is better. Make certain the coil voltage is correct (AC or DC - this is important as each has different characteristics) and the loads they connect to..
If uncertain, I'd go with contacts rated for inductive loads as their designed to handle sparking better.
Please let me know if it worked.