A build of the c3270 IBM 3270 (TN3270) terminal emulator is available for Maemo Bora. If you don’t have the Osmosoft repository you can add it by clicking here, and then find c3270 under user/Emulators in Application manager.
In the photo you can see c3270 running in one xterm tab whilst connected to Hercules running in another. Although there is no reason why you could not use this to connect from an internet tablet to your corporate IBM mainframe if you have one.
Disclaimer: This is provided as-is, without any warranty of any kind, and don’t blame me if this bricks your device or you realise after all these years of working with GUIs that text is better.