The problem that you're running into is caused by the fact that the tablets don't actually have a full and functional samba system setup. The only reason the tablet FileBrowser can see Windows shares is because the FileBrowser application itself implements a very basic "windows networking client".

Every windows machine with file sharing setup runs as it's own network server... when you want to access the files, you're automatically connecting to the server and making requests/writes. In the linux world the equivalent to this "windows network server" is an application called "Samba", that performs the same functionality. Unfortunately the tablets don't include a Samba server, so there's no way to just "connect to them" from windows networking. Take a look in the repositories and see if anyone's ported Samba over yet, but last time I looked a few months ago I couldn't find it.

Thanks,
-Rob