Removing comments from database.

I have just had to update my website which is using Gallery2, as the host company was changing MySQL4 to MySQL5. This is now working correctly but I have a query about something I noticed while migrating the database.

Some of the tables in the database are very large and I am not sure what these tables contain. One which is obvious is the 'Comments' table. This contains 4104 records and all appear to be spam. I do not have the comments module activated so I am unclear where they come from. Other large tables are : AccessSubscriberMap(4322), CacheMap(384), ChildEntity(4295), Entity(4322).

How do I remove all the comments, and entries in other tables if possible. Can I just delete the records from the database?

Gallery version = 2.1.1 core 1.1.0.1
PHP version = 4.4.9 cgi-fcgi
Webserver = Apache
Database = mysql 5.1.67-log, lock.system=flock
Toolkits = ArchiveUpload, Exif, NetPBM, Gd
Acceleration = partial/21600, partial/21600
Operating system = Linux infong 2.4 #1 SMP Wed May 15 13:26:15 CEST 2013 i686 GNU/Linux
Default theme = PGtheme
Locale = en_GB
Browser = Mozilla/5.0 (X11; Linux i686; rv:22.0) Gecko/20100101 Firefox/22.0

Integra Web Design
Huntly, Aberdeenshire
www.integrawebdesign.co.uk