In reply to mypyrex:
Is this the contract on your phone?
If it's a phone you can tether to (what type is it?), then tethering your tablet to it should be fine.
As said above, many contracts (particularly unlimited data ones) don't allow tethering, and they could disconnect you for it, but if you've already checked this you should be OK.
I've tethered my Nexus 7 to my Nexus 4 in the past, worked a treat.