I have the UNO board and I was wondering if it would be possible to use my keyboard to trigger functions on my board?
You could use it like a stick to press switches.
The keyboard, if it is a USB device, is a USB slave. So, is the Arduino. Two USB slaves can not talk to each other. A slave can only talk to a USB Host/Master.
There are USB Host shields available, and some drivers have been written for some USB devices.