Why do MOFET need so many contact windows?
A "contact window" is a loop that connects two materials (usually a metal and a semiconductor) together. Since they are square frames, they look like windows. The picture above is a two-gate mosfet with metal gates. For each of the three source/drains you can clearly see the contact windows, connecting the semiconductor islands to the metal pads. The gates do not need a contact windows in this particular design, as they are already made out of metal.

What leads to lower resistance and capacitance is not so much the contact window itself, but the fact that the signal travels the distance through metal instead of semiconductor.