I think there should be useful to add some boolean parameter like $useTablePrefix or maybe better string. For example, If your application is integrated with some forum and uses its "Users" table and application's tables prefix differ from your forum tables prefix
I agree with anli. The tablePrefix parameter is an application-level concept which should be solved in application-level code rather than in framework-level. If we provide this in framework, you may enjoy the convenience, but at the same time you and other users also need to learn more.
For the blog demo, a base AR class could be written which reads an application parameter about tablePrefix.