I'm not too sure about that Happy Toad.
The only reason that I challenge this is that I often go to trade shows (not as a magician) and often see magicians that are seated at a tbale that they, or the exhibitor provides.
I would 'guess' that this is something that you should have discussed with the company that you're representing and at the same time, asked about their products, the profile of the anticipated clients etc. but i see no reason why you shouldn;t at least explore the idea of having some table space and a couple of stools. It's sometimes nice if you;ve walked around an exhibition for hours to have a seat for five minutes

but this usually applies to one spec who's selected to assist, pick a card etc.
Having a table may open up much more opportunity to show more varied tricks.
I would personally look at an angle to promote the client's name as part of, or during your presentation. I've often seen people giving away stress balls, particularly at the health & safety exhibitions I've been to, or perhaps miniture sports balls if it were a sports and leasure exhibition.
If you discussed with your client the possibility of them providing some with their name printed on them then these would make great loads for a cups and balls routine whch could then be given away. I think that if you came up with these sorts of simple ideas then your client may begin to appreciate you even more.
Member of the Magic Circle & The 2009 British Isles Close-Up Magician of the Year
It's not really an optical illusion - it just looks like one!