Can someone explain how this is past please
It's not. The past tense would be Adtam egy tollat.
As a native speaker of both english and hungarian i would say "Adok egy tollat" is more like "i give you a pen".
"I give a pen" would be "Egy tollat adok"
Did I really just get the same sentence twice in one testing out of this lesson group where there must be many more sentences available? Weird.