Hi, Samsung Tech Support here.
You may be experiencing this issue because of your screen protector, or the materials it is made out of. Another cause could be that the screen has oil or another substance on it that is preventing your finger from making proper contact. Try removing the screen protector and wiping the screen off with a microfiber lint-free cloth..
If this solution does not resolve the issue, you could also attempt a Factory Data Reset, accessed through the OS by going to Settings > Backup and Reset > Factory Data Reset or if you are unable to get to Settings, simply power the tablet completely off and boot it back up by holding down the Power and Volume Up buttons to access Android System Recovery, once you've reached that text-based screen you'll use the Volume Up and Down buttons to maneuver the highlighter to "Wipe data/Factory Data Reset", and use the Power button to confirm, on next screen select Yes using the same method, and on the final screen select "Reboot System Now".
If none of these resolves the issue, it is most likely that your device requires service and you will need to either set up a service request on Samsung.com, or give us a call at 1-800-SAMSUNG
Thanks and have a great day!