It depends on what you are doing.
Do you have many apps open at once? (Just going to a different app doesn't close it). This can freeze up a device easily.
Are you playing games that are online rather than just on the tablet? This can freeze up the device.
Have you checked your data and/or WiFi connection to make sure that it isn't the problem (drops in speed, etc.)?
Also, when was the last time you restarted (turned off and back on) the tablet? If not done regularly this can lead to freezing due to the device being unable to access all resources.