JSFiddle - React, Tailwind, and code Playground

HTML

<table>
  <tr>
    <td valign="top">Disciplines :</td>
    <td>
      <table>
        <tr>

          <td width="30" valign="top">
            <input type="checkbox" name="Physics" />
          </td>
          <td width="200" valign="top">Physics
            <table class="physicsTable" style="display:none;">
              <tr>
                <td width="30">
                  <input type="checkbox" name="Acoustics" />
                </td>
                <td width="200">Acoustics</td>
              </tr>
              <tr>
                <td width="30">
                  <input type="checkbox" name="Cosmology" />
                </td>
                <td width="200">Cosmology</td>
              </tr>
              <tr>
                <td width="30">
                  <input type="checkbox" name="Nuclear Physics" />
                </td>
                <td width="200">Nuclear Physics</td>
              </tr>
            </table>

            <td width="30" valign="top">
              <input type="checkbox" name="Chemistry" />
            </td>
            <td width="200" valign="top">Chemistry
              <table class="cheTable" style="display:none;">
                <tr>
                  <td width="30">
                    <input type="checkbox" name="Chromatography" />
                  </td>
                  <td width="200">Chromatography</td>
                </tr>
                <tr>
                  <td width="30">
                    <input type="checkbox" name="Catalysis" />
                  </td>
                  <td width="200">Catalysis</td>
                </tr>
                <tr>
                  <td width="30">
                    <input type="checkbox" name="Geochemistry" />
                  </td>
                  <td width="200">Geochemistry</td>
                </tr>
              </table>
        </tr>
      </table>
      </td>

  </tr>




</table>
</td>
</tr>
</table>

JavaScript

$('input[name="Physics"]').on('click', function() {
    $('.physicsTable').slideToggle();
})

$('input[name="Chemistry"]').on('click', function() {
    $('.cheTable').slideToggle();
})