CEP is a publisher and not a bookseller with premises and a physical stall.
Single copies of the titles will be available to look at during the Congress and a leaflet to take away containing information about all titles. I believe there may be information about a book from the Peto Institute available in the same way, Susie Mallett is working on a pamphlet, and there may be others too.
Usually at conferences books are available to order, rather than purchase there and then. A catalogue or titles may be available to look at and a form provided to complete to obtain copies. Sometimes there are copies available to buy, but not often; for instance, if the congress is being held in the home country of the publisher it would be possible to take multiple copies to sell – perhaps SAHK will do this with their publications. No airline luggage restrictions for them!