Ho to get data from dynamic table

i am new to php and got a problem, where I can not find the right answer for. My goal is to print an invoice from a MySQL database, but instead of directly throwing it trough fpdf, I want to to create a page, where the user can edit the values, that are finally printed. I have realized this with a dynamic table which looks like that:

<?php
  while($aufstellung = mysqli_fetch_array($content)){
    $gesamtRechnungsSumme += $aufstellung['GesamtpreisZeit'];
    echo
    "<tr>
    <td><input type='text' name='w_type' value=".$aufstellung['w_type']."></td>
    <td><input type='text' name='dauer' value=".$aufstellung['Dauer']."></td>
    <td><input type='text' name='price' value=".$aufstellung['price']."€"."></td>
    <td><input type='text' name='gesamtzeit' value=" .$aufstellung['GesamtpreisZeit']."€"."></td></tr>";
  } 

But now the amount of fields in table varies for every invoice. So how can I grab every single value as a constant like $_POST['XY'] in my fpdf page?

Thank you for every idea.