SSH
SSH (Secure SHell) is a network protocol that allows you to access a terminal shell remotely. This is particularly useful when performing complicated console operations on the tablet where their limited text-input may get in the way.
OpenSSH
OpenSSH is the preferred client and server package. It is available in Extras. You can install either only the client or server, or both depending on your particular use-case. Be aware that the installation may take a while and appear frozen, as SSH keys have to be generated during the install.
Usage
Client
You can connect to a remote machine from the tablet by running ssh user@server ip. This will give you a remote shell on the server machine.
Server
If you wish to access a shell on the tablet from a remote machine (to edit a local file with a real keyboard, perhaps), then all that you need to do is make sure OpenSSH server is installed on the tablet and ssh root@tablet ip