Before I ask the question, here is my understanding about Controller in MVC pattern.
Common practice is to create a controller associated with each view. When the application is using Restful URL design, this usually maps to the index, new, edit and delete actions. You can then map an method to handle each action.
http://example.com/examples/1/edit - maps to edit method on ExamplesController
http://example.com/examples/1/new - maps to new method on ExamplesController
http://example.com/examples - maps to index method on ExamplesController
http://example.com/examples/1/delete - maps to delete method on ExamplesController
http://example.com/users/1/edit - maps to edit method on UsersController
http://example.com/users/1/new - maps to new method on UsersController
http://example.com/users - maps to index method on UsersController
http://example.com/users/1/delete - maps to delete method on UsersController
After working on ASP.net MVC and rails, I think Controller should create per Resource (in the REST style application).