Would it be plausible to over see 2 tables of a particular game, each being it's own event, and benefit from the player hours from both or would the system not allow it?
I attended a few events last year that had one person covering multiple tables. Most of these were companies running several simultaneous events (CMON, Gale Force 9), and had several volunteers working. If you’re a lone host, trying to double up on your hours, not sure how that would work.
You can run an event for as many players as you want; the event system has no concept of how many people can play a game. Just consider how well you will be able to manage those multiple tables if, for example, your event is full of players who have never played that game system before.
One thing I've done in the past with board games I know well is run an event with enough player slots for two games. Ideally I'd get enough experienced players to split them up into "experienced" and "learning" games. If not, then I sit between them and answer questions as they come up.
That is actually a really good idea to split the large single group into 2 smaller ones within my event. Looking at Munchkin as a good example, most sets have similar base rules with themed ones having special rules added on top.