Well either your battery needs to be charged, which you should do while the tablet is off at this point, the software is having problems and you need to "Hard Reset" the device (which would wipe all data), or the device needs service/repair.
If the tablet is under warranty still. Contact the manufacturer to see about them repairing or replacing it.
If it isn't under warranty any longer, then it is up to you if you want to try the "Hard Reset", or take it somewhere to have it repaired. The instructions on how to the the "Hard Reset" are listed below.
NOTE: Doing this will clear 'all' the data on your tablet, so it is suggested you not choose this option unless you have to, or aren't worried about losing anything on the device.
Be...