Info, as far as I know it:
The table is 6'x3'—a standard table size. Not the most comfortable bed (don't ask), but plenty big for artists =D (I would have been fine with just the half-table originally alotted, but then again, I have NOTHING by way of fanart for things other than BA, FoD, and Shadows (which can't be considered fanart because a) they're webcomics, and b) they're MY webcomics o_o;) so I don't expect very many people to be interested.
As for things other than artwork... if it's made by you, as far as I can tell, it's fine. That means that selling Slayers manga is out; selling Shadows manga (if Akadot would kindly ship my TONE @___@;;) is in =D T-shirts, mugs, posters, bookmarks, and that ilk is fine, as long as it's made with YOUR art, NOT others'.
That said, I'm not sure where selling the artwork of friends comes in. If they're at the table with you, then yeah, wind's your thing, but if they're not even at con, I dunno... that was never an issue that came up with me, as Aslua is made up of seven writers and one artist (me, in other words), so the only art I'm selling is my own.
Walking away is something I do plan on doing (unless my foot isn't not-broken by the time Con comes around @@;), but I'm not about to leave my stuff there. This is what hotel rooms are for =D
As for the other stuff... I'm not sure. There's a VERY limited number of tables, to be sure, and I don't know how many people have grabbed one besides myself.
Most of my sellables (which looks like it's going to be mostly prints. Bleh) are being printed through my home printer (an Epson... something that prints up to 13" wide). Kinko's or CafePress looks like my other option for things wider than 13" (for example, the traditional anime poster is 15" x 21" or thereabouts, and I loathe to have my poster be the smallest on the wall >>). CafePress offers a discount on bulk orders, and while I'm not the fondest of the quality of their T-shirt transfers, their other stuff is quality enough for me. It just needs to be ordered SOON or I'm not going to have it in time to pack up for the plane =D;;
On sprucing up the table, I think being in costume is probably one of the shinier things you can do to attract browsers (hence why I'm making a really flamboyant hat XD;;). The only other tactic I've found artists to do to attract people is just to have good artwork, which is another reason I'm going to make NONE of my con expenses back this year XD;;