JSFiddle - React, Tailwind, and code Playground

HTML

<table  class="table table-bordered table-hover">
				<tr>
					<th id="col1">Datum / Anzahl</th>
					<th id="col2">Text</th>
					<th id="col3">Einzelpreis</th>
					<th id="col4">Gesamtpreis</th>
				</tr>
				
			<!-- Einzelpositionen -->
				<tr>
					<td align="left" class="editCell">
						<span class="input">
							<input type="text" value="<?php echo $eventDatum ?>">
							<span class="glyphicon glyphicon-ok" aria-hidden="true"></span>
							<span class="glyphicon glyphicon-remove" aria-hidden="true"></span>
						</span>
					</td>
					<td align="left" class="editCell">
						<span class="input">
							<input type="text" value="<?php echo $eventTxt ?>">
							<span class="glyphicon glyphicon-ok" aria-hidden="true"></span>
							<span class="glyphicon glyphicon-remove" aria-hidden="true"></span>
						</span>
					</td>
					<td align="right" class="editCell">
						<span class="input">
							<input type="text" text-align="right" value="<?php echo $ePreis ?>">
							<span class="glyphicon glyphicon-ok" aria-hidden="true"></span>
							<span class="glyphicon glyphicon-remove" aria-hidden="true"></span>
						</span>&nbsp;<?=$waehrung ?>
					</td>
					<td align="right" class="editCell">
						<span class="input">
							<input type="text" text-align="right" value="<?php echo $gPreis ?>">
							<span class="glyphicon glyphicon-ok" aria-hidden="true"></span>
							<span class="glyphicon glyphicon-remove" aria-hidden="true"></span>
						</span>&nbsp;<?=$waehrung ?>
						
					</td>
					<td class="no-border">
						<span class="glyphicon glyphicon-plus" aria-hidden="true">plus</span>
					</td>
				</tr>

				
			<!-- Summen und MwSt -->	
				<tr>
					<td align="right" colspan="3">Zwischensumme</td>
					<td align="right">
						<span class="text"><?php echo $nettoSum ?></span>
						<span class="input">
							<input type="hidden" text-align="right" value="<?php echo $nettoSum ?>">
						</span>&nbsp;<?=$waehrung...

JavaScript

$('table').on('click', '.glyphicon-plus', function() {
		var $tr    = $(this).closest('tr');
	    var $clone = $tr.clone();
	    $clone.find(':text').val('');
		$clone.find('span.text').after('-kopie');
	    $tr.after($clone);
	    
	});