Hello and Sorry for my bad english.
To enable multi-user at the tab 3 10.1, first you musst root your stock rom.
Then instal BusyBox from the playstore open it and instal.
Now you take a build.prop editor (maybe from playstore) and open, now add a new property.
Name it: fw.max_users
At the key you fill how many users you want (2 at my tab)
Save and Reboot!
Now in the options, you shold can add new users.
To enable multi-user at the tab 3 10.1, first you musst root your stock rom.
Then instal BusyBox from the playstore open it and instal.
Now you take a build.prop editor (maybe from playstore) and open, now add a new property.
Name it: fw.max_users
At the key you fill how many users you want (2 at my tab)
Save and Reboot!
Now in the options, you shold can add new users.