Occasionally Android devices and more specifically Galaxy tablets can sometimes experience multiple letters being typed or screen freezing.  This issue appears to be with the standard keyboard used in these devices.

A solution that has been found to remedy this issue is to install a new keyboard.  Googles Gboard appears to work best.  Once Gboard is installed the issue should be resolved.  If it is not then turning off auto correct, everything under glide typing and sync learned words should solve the issue.

If you have further problems or have a different issue please contact support.