In order to do a factory reset for your tablet, you need to go to Settings > Privacy > Factory data reset. By doing this, you will lose all your data. If you want to do a hard reset of the device, you need to turn it OFF first. After you did this, press and hold the Volume Down, Menu and Power button until the screen flashes and the Android logo appears. This is the sign that the tablet entered the Recovery Mode. To complete the process, you need to choose Wipe data / Factory reset from the menu provided.