Admin Table

/*
 * Add Page Template Column on Admin Page Table
 */
function asiq_page_column_views( $defaults ) {
	$defaults['page-layout'] = __( 'Template' );
	
	return $defaults;
}

add_filter( 'manage_pages_columns', 'asiq_page_column_views' );

function asiq_page_custom_column_views( $column_name, $id ) {
	if ( $column_name === 'page-layout' ) {
		$set_template = get_post_meta( get_the_ID(), '_wp_page_template', true );
		if ( $set_template == 'default' ) {
			echo 'Default';
		}
		$templates = get_page_templates();
		ksort( $templates );
		foreach ( array_keys( $templates ) as $template ) {
			if ( $set_template == $templates[ $template ] ) {
				echo $template;
			}
		}
	}
}

add_action( 'manage_pages_custom_column', 'asiq_page_custom_column_views', 5, 2 );