JSFiddle - React, Tailwind, and code Playground
HTML
<table id="insSpecc" width="100%;">
<div class="separator">
<tr>
<td><span>Product</span></td>
<td><span>Mfd_date</span></td>
<td><span>RRX(Qty)</span></td></tr></div>
<tr>
<td><select id="prod_name" name="prod_name">
<option>Balloon</option>
<option>Nachos</option>
<option>Cola</option>
</select></td>
<td><input type="text" id="mfd_date" name="mfd_date[]" size="5"/></td>
<td><input type="text" id="client_rrx" name="client_rrx[]" size="5">
</td>
<td>
<button id="add_img" onClick="insSpec()">Add</button>
</td>
</tr>
</table>
JavaScript
function insSpec()
{
rl=document.getElementById("insSpecc").rows.length;
var a=document.getElementById("insSpecc").insertRow(rl);
var h=a.insertCell(0);
var f=a.insertCell(1);
var m=a.insertCell(2);
var n=a.insertCell(3);
h.innerHTML='<div class="separator"><select id="prod_name'+rl+'" name="prod_name"><option value="balloon">Balloon</option><option value="nachos">Nachos</option> <option value="cola">Cola</option></select>';
f.innerHTML='<input type="text" name="mfd_date[]" id="mfd_date'+rl+'" size="5" />';
m.innerHTML='<input type="text" name="client_rrx[]" id="client_rrx'+rl+'" size="5" />';
n.innerHTML='<button class="del_img" onClick="delSpec(this)"/>Delete</button></div>';
}
function delSpec(node)
{
r=node.parentNode.parentNode;
r.parentNode.removeChild(r);
}