Midori is Linux. You'll need to understand basic Linux/Unix commands, and realize that most of the commands are "hosted" by busybox, which doesn't give you the full functionality of the "native" commands.
You can't run Word and Excel on Linux. You can run OpenOffice, but since it's such a huge program (around 100MB footprint), and needs memory to run - forget it. You might run some of the simpler (WordPad-like), Linux derivatives, but that's about it.
The only other choice is to use your IA-1/Midori more as a terminal using the VNC Client to attach to your PC (or to your Linux box), and running Word/Excel through that.