If the screen itself is still visible but the digitizer is broken, connect a mouse to the tablet using an "on the go" adapter. If the tablet supports OTG, a cursor will appear on the screen, and from there you can unlock the tablet. If you can't see the screen or OTG is not supported, there's no way to unlock the tablet that I know of. At that point, connect the tablet to a PC and pull off all the data you can. On a device running a nearly stock version of Android, you would need to interact with the system to change from charging mode to file transfer mode, but not TouchWiz. TouchWiz by default opens up in file transfer mode.