The proper table for this would be cmdb_ci_web_site. As with many other things in the ServiceNow OOTB configuration the name doesn't exactly match how everyone thinks of them. We think of them as domains or fully qualified domain names. If you do a search in the system tables you'll see that there are many tables that have "domain" in their name, many having to do with Active Directory domains.

There are all the fields that you'd expect for a web site including DNS domain, fully qualified domain name, IP address, the type of web server used and of course a bunch of other informational fields like description and all the available assignment fields for both users and groups.