Hello Judi, The Supplier Categories report has to do with custom tags created by your account to tag venues like "large meetings only." At this time, the best report that would show square footage would be the Compare Suppliers report.
Here's a great instructions article on the comparison reports: https://support.cvent.com/apex/CommunityArticle?id=000001121
Hello Judi, Unfortunately, there isn't a way to mass export information on venues. The reason is to protect the integrity of our data. However, you can search and add the properties manually to your venue list. For easier selection, you can use the "Union" category to filter. This would allow you to see square footage and compare venues.
Let me know if you have any questions or need further assistance, I can request some direct assistance for you.