The tablet part is the computer. You can't use only the keyboard.
As per above, I also doubt the keyboard has HDMI. Looks like USB only but I can't tell from the pictures.
Either way, it doesn't change the fact you need the tablet part.
This is a confusing question as I can't picture your problem. You didn't mean the "keyboard" gets in the way did you? If so, and the keyboard blocks the HDMI connection you'd have to use this without the keyboard.