You may have to do a factory restore and start over. some apps are not compatible with the s7-slim. Also if you're tablet is not rooted, do not install a 3rd party launcher, as it will make your screen non-responsive.
This will reset to factory settings and you will have to reinstall your apps. Download the firmware for your device. Unzip the file and copy the entire dload folder(inside there are 2 files) to your memory card. I suggest you copy the firmware to blank formatted memory card. Remove the battery to power it off, insert your memory card, put your battery back in and power up. Your tablet should automatically install the new firmware. When the screen says ok, remove the memory card before you press the power button to reboot.