How do you load a current database with a lot of data inside it, to isolated storage. I've read little of using database in phone 7 however they don't load any predefined data. Rather they've created a database if it's running the very first time use later exactly the same.

You'll be able to give a database for your project, however it are only able to be utilized in read-only mode. If you wish to read/email it, you need to add code which will copy the information to some separate database after install. From it:

Utilizing an Existing Database You can ship a current database together with your application with the addition of it for your project and setting the Build Action to Content. This can deploy the database file together with your application to the phone, but it will likely be put into exactly the same folder as other static content for the application. The application can only read out of this folder, and that means you either need to open the database in read-only mode, or copy the database across into Isolated Storage before being able to access it. This is a good example connection string for any database which has been packed using the application: