dbo.DTA_* tables in MSDB I ran Brent Ozar's sp_blitz on one of my production server.  IT tagged a few tables in the MSDB database as being user created.  They all follow the pattern dbo.DTA_*.  Do these table come with MSDB, or were they added by something/someone?
These are likely left over from Microsoft's Database Tuning Advisor. You should be able to get information about the sessions with this stored procedure:

EXEC sp_DTA_help_session


After identifying the sessions that you do not need you can remove them with this stored procedure supplying the session id using one as an example:

EXEC sp_DTA_delete_session 1