Hard Reset SAMSUNG T377P Galaxy Tab E 8.0" LTE

First method:

At the very beginning hold down the Power key for a short while in order to turn off the device.
After that, press and hold simultaneously the Volume Up + Home + Power button for a few momements.
You should release held keys as soon as the Samsung Logo appears on the screen.
Afterwards select "wipe data / factory reset" by using Volume buttons to navigate and Power key to confirm.
In the next step choose "Yes -- delete all user data" to confirm whole operation.
When the Recovery Mode appears again select "reboot system now".
Excellent! You have just performed the hard reset operation.