James D. Macdonald said:
"Suite" in this case may be a fancy name for "PO Box." A mail-forwarding service?
Suite may also be a fancy name for "suite." It is not uncommon in NY (or other cities) for a "suite" on a given floor to contain thousands of square feet and dozens of individual offices.
It is also not uncommon for multiple companies to rent out office space in an individual suite. Usually there is a communal reception area and in many cases a communal receptionist that all the companies chip in to pay for and share. In these shared suite situations companies also share copy rooms, faxes, etc.
Often times the companies who share a suite are in the same industry (i.e. a bunch of small boutique lit agents). This is a fairly common set-up in LA for production companies, small agencies, casting agencies, etc.