I do not know if you still need this answer or it's been answered already, but for the benefit of all: Yes, artists need to man your own tables or get someone they know to do it for them, the con has nothing to do with anything that goes on at your table other than providing you the space and of course reserving the right to remove objectionable materials (ie sex/nudity images etc) if they are present and are not screened for appropriateness (put sticky notes over the graphic bits or something, s'what I suggest, it's worked at other cons it'll work here just make sure they stay in place and people thumbing through don't remove the stickies).
If you request an artist alley/common market contract from exhibitors@kumoricon.org, however, you'll see all these details, so that is the best thing to do if you are considering getting a space. Tables of this sort are reserved at a price of $25, for this year.
