when charging the screen does nothing but flash off and on why

Hey Jenifer, perhaps the battery is dead/dying. How old is the tablet? I am not sure how technically minded you are but these batteries are really cheap but will require a certain amount of skill to open the tablet and desolder the old battery from the board. It Is a fairly straight forward procedure, just google it and don’t worry if you can’t find you exact model, androids are all very similar.