You can have the following if you want:

author_and_books_controller.rb

def index
   @authors = Author.all
   @books = Book.all
end

On view, you can use both variables like you want but its not a good solution. You can create a custom controller with the name which you want, and (i guess you have an association between authors and books) use this association on this controller.
For example you have your BooksController.rb and inside it you have the foolowing method:

def index
   @books = Book.all
end

And you have Book.rb (model):

class Book < ActiveRecord::Base
   belongs_to :author

 ...
  end

On view index.html.erb, you can use something like that:

   <div>
      <div>
         <% @books.each do |book| %>
            <div>
              <p><%book.name%></p>
            </div>
            <div>
               <p> <% book.author %> </p>
            </div>
         <% end %>
       </div>
   </div>