You can try to factory reset the tablet. Doing so will wipe all user data/apps from the tablet.
# Make sure the tablet is charged. Losing power while performing the factory reset may brick your tablet.
# Turn the tablet off.
# Hold the [volume up] button and the [power] button. Continue holding until you see “Android System Recovery” show on the screen. Release all buttons after you see that.
# Use the volume buttons to scroll to the “wipe data/factory reset” option. Use the [power] button to select it.
# Press the [power] button to confirm the user prompts.