<table>
  <tr class="row">
    <td>Value 1</td>
    <td>100</td>
  </tr>
  <tr class="row">
    <td>Value 2</td>
    <td>2000</td>
  </tr>
  <tr class="row">
    <td>Value 3</td>
    <td>500</td>
  </tr>
</table>

$(document).ready(function() {
  $(".row").each(function() {
    var value = parseInt($(this).find("td:nth-child(2)").text());
    if (value >= 1000) {
      $(this).css("background-color", "yellow");
    }
  });
});