If it's not there, then either your ROM is messed up somehow, or the menu item is hidden extremely well, or Samsung chose not to include the Users functionality in your ROM, period.
There is a way to force your device to display the Users setting screen; working or not. You just need to launch the
Users activity in
com.android.settings. One way to do that is by installing Nova Launcher, adding the Activities widget to the homescreen, and choosing that activity from the list.
If that still doesn't work, then your device really does not include the Users functionality (which is surprising, as it's a tablet).