Credit goes to Newton1221 on the Xoom Forum of Android Central. I've tested it and it works for the Galaxy Tab. Original post is
here.
Skip Step One! I accidentally included it, but I don't want to delete it now for fear of creating more confusion as it is referenced below.
1: on Galaxy Tab, go to settings>wireless & networks>tethering and portable hotspot and make sure that "Bluetooth Tethering" is UNCHECKED, this is NOT what we want
2: on Galaxy Tab, go to settings>wireless & networks> enable airplane mode
3: on Galaxy Tab, go to settings>wireless & networks> enable bluetooth
4: on your android phone, go to settings>wireless & networks (or equivalent)> enable bluetooth
5: Make sure that both devices are discoverable, so that they can see one another, should be in settings>wireless & networks>bluetooth settings
6: on Galaxy Tab, go to settings>wireless & networks>bluetooth settings>select your phone in order to pair it with your Galaxy Tab
7: a box should pop up on both devices, select Pair on both devices
8: on Galaxy Tab, once the pairing is complete (still inside bluetooth settings), select the phone, it should say paired but not connected underneath it
9: The two devices should connect, once connected there should be a wrench next to the connected device, clicking on this will show an option to tether, click this option if it is not automatically enabled
10: TA-DA, if it worked then in the bottom right hand corner of your Galaxy Tab should have two bluetooth icons, one should indicated that your bluetooth is turned on and the other should say bluetooth tethered, you are now using your phones internet data plan on your Galaxy Tab