This might be an issue regarding the system itself, a virus or insufficient memory inside the tablet. First I would try shutting down all apps that are open, and restarting the device. If that does not work, try using an anti-virus software, such as Norton mobile security. If that does not work, check the amount of RAM you have installed into the device. Installing more GBs of memory could greatly increase the speed of the tablet.
Hope you fix the tablet!
-Toby