There isn't an option for to reset to Factory Default within the system menues.
To open the Factory Reset you have to power OFF the tab first.
Power ON the Tab using the Power Button
As the Tab starts directly press the big Home Button in front of the screen for about 3-4 sec
There will show up a Triangel with caution mark and an Android
Android System Recovery V.1.0 will start.
Now you'll have the choice between:
reboot system now
Update from sdcard
factory reset
wipe cache partition
To move between the choices use the Volume UP or DOWN key and use the big Home Button for to select your choice.