Electrical issue, breakers not tripped but outlets dead
It sounds like the heavy load caused a failure. I usually start at the closest outlet to the breaker panel that is not working if that one is good the last working one on that circuit. This is where I find 98% of all failures of this type and it is usually from back stabs (the #14 awg wire is stuffed in a hole in the back of the outlet) it could be a bad connection from a wire nut or even a broken wire but my experiance is it is usually a bad backstab. If you pull an outlet out and everything starts working replace the outlet or this will happen again.i just read this again and the one issue I did not discuss was the broken tab. This could be to support a multi wire branch circuit 2 breakers 1 on top outlet and the other on the bottom outlet , the second case is if one of the outlets was switched usually for a light when a ceiling fixture was not installed.
If OP has abandondened this question I would vote to close, so we don't see it come up again and I did try to answer the first time, now a second if no OP comment or up vote it should be purged as this is a waste of our time imo.