If you have software trouble with your galaxy tab,or have to many wrong pattern unlock then forgot your email and password you can try to hard reset your phones to get it back to default factory state.
Here how you perform hard reset to your galaxy tab 10.1
1.turn off your device
2.hold volume down + power key wait till the boot menu shown up
3.select the left (recovery mode) by navigating the volume button then confirm selection by pushing the power key
4.navigating to the wipe data / factory reset by selecting the volume button than confirm your selection again with the power button.
5.wait till the operation completely finish then reboot your device.
You also can see this video how to hard reset your galaxy tab
NOTICE:
By doing this hard reset method you will lose all your internal phone storage data!!.