problem in understanding mul & imul instructions of Assembly language

Question

I\'m learning 80386 from PC Assembly by paul caurter

  mul source

• If the operand is byte sized, it is multiplied by

Answer 1

Q1/Q2: I think the reason is historical. Before 32-bit was an option, there was no eax or edx. The 32-bit functionality was added to be reverse compatible.

Q3: The low order bits are going to be in eax. Those are the only ones you care about unless there's overflow into the high bits.

Q4: Definitely an odd table. I think you get it though.