manage_pages_custom_column

add_filter( 'manage_pages_columns', 'page_column_views' );
add_action( 'manage_pages_custom_column', 'page_custom_column_views', 5, 2 );
function page_column_views( $defaults )
{
	$defaults['page-layout'] = __('Template', 'textdomain');
	return $defaults;
}
function page_custom_column_views( $column_name, $id )
{
	if ( $column_name === 'page-layout' ) {
		$set_template = get_post_meta( get_the_ID(), '_gc_page_template', true );
		if ( $set_template == 'default' ) {
			echo __('Default Template', 'textdomain');
		}
		$templates = get_page_templates();
		ksort( $templates );
		foreach ( array_keys( $templates ) as $template ) :
			if ( $set_template == $templates[$template] ) echo $template;
		endforeach;
	}
}

// Add the custom columns to the book post type:
add_filter( 'manage_book_posts_columns', 'set_custom_edit_book_columns' );
function set_custom_edit_book_columns($columns) {
    unset( $columns['author'] );
    $columns['book_author'] = __( 'Author', 'textdomain' );
    $columns['publisher'] = __( 'Publisher', 'textdomain' );

    return $columns;
}

// Add the data to the custom columns for the book post type:
add_action( 'manage_book_posts_custom_column' , 'custom_book_column', 10, 2 );
function custom_book_column( $column, $post_id ) {
    switch ( $column ) {

        case 'book_author' :
            $terms = get_the_term_list( $post_id , 'book_author' , '' , ',' , '' );
            if ( is_string( $terms ) )
                echo $terms;
            else
                _e( 'Unable to get author(s)', 'textdomain' );
            break;

        case 'publisher' :
            echo get_post_meta( $post_id , 'publisher' , true ); 
            break;

    }
}