I'm the original asker for this question and decided to clarify. If I buy a tablet that comes with a year of Office 365 Personal I would think that it comes with a card that has a product key on it. If I wanted to give that office away I just take that card with a code on it, hand it to someone else and say "Here you go, enjoy Office." If it was simply a product key on a card that would be easy (assuming that sort of thing is legal).
However, from what I understand when you get one of these tablets it's not just a card in the box but rather Office 365 is automatically activated when you register the tablet. If that's the case would it even be possible to give it to someone else?
This could also apply to someone who is currently subscribing to Office 365 Home, a Personal subscription would be worthless to that person. Surely there is a way for them to offload that free year of Office Personal to someone who could actually put it to use.