If the "Safe Mode" is still running after you restart your tablet, I would then check to make sure your "Volume Down" button is not stuck. Check to see if it has anything stuck in it as well, dust, etc. Anything like this can cause the tablet to go into, and get stuck in, "Safe Mode".
If that doesn't work try this...
Use the "Status Bar" to turn off "Safe Mode'. Pull down (swipe) the "Status Bar" of your phone. Now tap the "Safe Mode" button. This should turn "Safe Mode" off. Now your tablet will automatically restart, so that it boots up out of "Safe Mode".
And lastly...
If you want to get rid of/disable "Safe Mode".
1. First turn off the tablet.
2. Next press and hold "Power" until you see the manufacturers logo on the screen...