Also calledExhibitor listShow directoryExhibitor catalogue
It is the largest part of your site
A show with four hundred exhibitors has four hundred pages of specific, factual content about companies and product categories. That is far more search surface than the rest of the site combined, and it is the part that matches what buyers actually type.
What a listing needs
Company name, a real description rather than boilerplate, product categories, stand number and hall, the brands they represent, and links to their own site. Categories matter most: they are what a visitor filters by in the hall and what a search engine matches against.
Behind a login is a wasted asset
Directories hidden behind registration cannot be indexed, so they bring in nobody. Publishing them openly costs nothing — the exhibitor wants to be found — and each listing is a page working for you between editions.