Example of how to use jQuery to add an 'empty' row when the category you select on Table View Template does not have any events.

tw_ee_espresso_events_table_template_empty_row.php

<?php // Please do not inlue the opening PHP tag if you alread have one.

function tw_ee_espresso_events_table_template_empty_row() {
    wp_add_inline_script( 
        'espresso_events_table_template',
		'jQuery(document).ready(function($){
			$("#ee_filter_cat").change(function() {
				$(".espresso-table-row.empty").remove();

				if( $(".espresso-table-row:visible").length === 0 ) {
					var markup = 
					"<tr class=\"espresso-table-row empty\"><td colspan=\"4\">Sorry, there are no classes scheduled with that parameter. Please contact <a href=\"mailto:Alice@rmf.org\">Alice@rmf.org</a> for more information.</td></tr>";
					$("#ee_filter_table tbody").append(markup);
				}	
			})
		});'
    );
}
add_action( 'wp_enqueue_scripts', 'tw_ee_espresso_events_table_template_empty_row', 11 );