$(function() {
  var min = 0;
  var sec = 0;
	$('table tr').each(function(e) {
		var tr = $(this);
		var phone = tr.find('td:nth-child(8)');
		var time = tr.find('td:nth-child(10)');
		if(phone.text()=='Телеф.') {
			sec += parseInt(time.text().replace(/(\d+):(\d+)/, '$2'));
      if(sec > 60) {
        min++;
        sec = sec - 60;
      }
			min += parseInt(time.text().replace(/(\d+):(\d+)/, '$1'));
		}
	});
  console.log('Минут: ' + min + ', секунд: ' + sec);
});