Default Win8.1 & Office question in the new tablets

Hi.

Would you know the answer to these 2 questions :

1. Could I use the OFFICE key that is provided with these new win8.1 tablets on my desktop PC? (and use it only there instead of the tablet) ?
2. Could the windows from the tablet (licence key) be used for a desktop ?

I'm looking at these tablets as a cheap source of OS & Office ... should yo be able to confirm this for me.

Thank you in advance.

Z