To add to what Erwin said, if you're using the simple built-in database you can also find the files under deployment\data\database\hsqldb
This depends on the database that you are using. If you're using the built-in database the modeler has an option in the console screen (by default at the bottom of the screen) under the advanced menu called Start built-in database viewer. With this viewer you can access the database. If you're using postgres, MS SQL or Oracle as database, you can use the tools that come with these databases.