jQuery does not bring the contents of a form element if inside a table element on an ajax load

Answer 1

You can't have a <form> directly inside a <tr>, so the invalid HTML is probably being tossed.

Given your <form> and input elements, it looks like this layout for a row would work:

<tr>
   <td>Value1</td>
   <td>
     <form>
       <input type="hidden" name="id" value="1"/>
       <button>Submit</button>
    </form>
  </td>
</tr>

Alternatively if you're submitting via AJAX, you could serialize the row yourself, but this approach won't degrade well, so I'd advise against it when possible. IMO <form> tags should be able to encapsulate a row, it'd be tremendously handy, unfortunately that's not the case.