Alf's close - this Post Reply page for example when I wrote this said 0.026 seconds with 15 queries. This means one or more files in the database(s) were hit with 15 requests for information in order to bring up this page. This possibly includes queries for validating me making the request in the first place, pulling up user IDs and accompanying avatars for each poster so far, etc.
Since I don't know the DB schema (the way the databases are organized, it's hard to tell exactly what was being queried and why.