The modem can't tell you what your computer or other devices are doing, only if they are or aren't using data. That's it. It only transmits the data.
With that said, as you may have read on these boards, one of the best programs to install on your computer to help you determine what, on that computer, is using data, is Glasswire.
The Hughesnet website will not use any more data than any other basic website.