<form id="sizePicker">
Grid Height:
<input type="number" id="input_height" name="height" min="1" value="1">
Grid Width:
<input type="number" id="input_width" name="width" min="1" value="1">
<input type="submit">

function makeGrid() {
  for(let td_row=0; td_row < 6; td_row++){
    $(<tr></tr>).appendTo(<table id="pixel_canvas"></table>);
for(let td_cell =0; td_cell < 6; td_cell++){
      $(<td></td>).appendTo(<tr></tr>);
    }
  }