Sharing a database with two applications

I recently signed up for hosting and one database (sql). I plan to host at least one mvc 2 web app and one wcf service - both of which use databases. Since neither need much space I was planning to use the one database with a prefix to indicate which table is associated with which app.

I was able to get mvc app's database (which is the standard ASP Membership) up and running by creating it locally and then importing the mdf file to create the tables I needed on the live database.

Now I'm trying to get my other application working with the database. I am getting an error when I try to write to it, which I think is because the table doesn't exist in the database yet. Should the entities framework automatically create a database table if it doesn't exist, or do I need to write scripts to do that, or is there a way to import tables from an mdf file whiteout clearing the tables already in the database?

Thanks!