I think this is a great idea!
I usually attend all the "big" conventions in Sweden, except for a J-pop convention where the majority wants manga and/or BL comics (which are two things I don't make xD).
It'd be pretty cool to have a roll up banner, where Tapas logo could be on top, and then maybe have the page pretty much blank so that you'd be able to maybe, perhaps, set up posters on the banner?
That way, more people could use the banner instead of only one!
(I'm not familiar with banners, so I do not know if it's possible to tape on the material)
Bookstands are also a great idea! It makes the table look more professional
Bookmarks as well as stickers are also very good ideas. People enjoy free things and bookmarks tends to go well with con goers.
But maybe consider brochures/flyers with info on? Could include the artists of said countries comics (would be re-usable within the country then!)
I think this is a splendid idea! We all know how expensive international shipping can be, however. My concerns in this case would be: Who's gonna pay for the shipping inside said country?
/// of topic:
((which con are you gonna attend? Maybe we'll see each other? In that case, I'd love to stop by and say hello to you!)