The first table is the Blog_Entries table and the second is the Blog_Comments table.

Select Top 150 * From blog_Entries
Where BlogID = 25
Order By AddedDate

The SQL Server code above will display 150 entries from the blog module you determine to be the module on your site. If you only have one site and one blog module than all the entries will have the same BlogId. Look through the records from the script above and record the EntryIDs for all entries you want to remove from your site.

Delete From blog_comments
Where EntryID In (1,2,5,...) 

Now delete the comments associated with the entries you wish to delete by running the SQL code above. SQL can be run within a DNN portal through a screen available under the Host menu.

DELETE From blog_Entries
Where BlogID = 25
And EntryID In (1,2,5,...)  

The final step is to delete the entries themselves as you can see above. I pinged my site (one other than CapturedTech.com) after performing these operations in hopes that Google would recognize the changes and adjust my Page Rank accordingly.