The person who buys the table will be making a contribution minus any personal benefits that he or she directly receives from attending, so the value of his or her meal, but not the others. With respect to that contribution, in this case I would assume most of the $500 would be reported as part of the regular reporting on contributions either through the quarterly reports that parties file or the annual reports, and whether or not it's caught by the regime there.
On October 3rd, 2017. See this statement in context.