Well it could be the tablet, or it could be something that got installed after you got it that is causing problems. Try loading the tablet in "Safe Mode" and see if it will completely turn on. If it does, then there is something that got installed on the tablet that is the problem. Remove whatever was added and it should work fine (then just reboot to get out of "Safe Mode"). If that doesn't fix it, then I would contact the place you bought it from and get them to replace it.
To get into "Safe Mode" please do the following.
1. First turn off the tablet.
2. Next press and hold "Power" until you see the manufacturers logo on the screen, then release the power button.
3. "Quickly" press "Volume Down" and hold it for few seconds until you see the message "Safe mode: ON" or something similar.
4. If you wanted disable it, simply repeat the steps above, and you should see "Safe Mode: OFF" rather than on.