HTMLTableElement.deleteTHead()

<table>
  <thead>
    <th>Name</th>
    <th>Occupation</th>
  </thead>
  <tr>
    <td>Bob</td>
    <td>Plumber</td>
  </tr>
  <tr>
    <td>Jim</td>
    <td>Roofer</td>
  </tr>
</table>

let table = document.querySelector("table");
table.deleteTHead();