MySQL table relations, inheritance or not?
I would recommend that you have a Pages table that contains both Static, Blog and any new pages you may have. The Pages table would have the columns page_url, page_content and pagetype (a tiny integer) which will help you differentiate between different pages. Later u may end up with other page types which have content hence leaving page content as a field in the pages table and may also allow you to have custom PHP or markup content in a blog page for customization (thinking aloud) 

You can then have a BlogPages table which has the information for blog pages linking to the categories and posts.