You aren't alone!!!! Subject line is unfair to MS Word, it isn't the problem, the hardware is and it happens with various programs.
I have a Dell Inspiron laptop with Windows 10.
One solution that helped a bit was to put a piece of cell phone plastic screen protector on the touchpad to reduce its sensitivity (I assume).
Best result was getting into the setup for the Dell touchpad and disabling any features you don't need and maximizing things like palm rejection. It has now become not too bad. Prior to changing the settings I was going to throw the thing into the street.