JSFiddle - React, Tailwind, and code Playground

HTML

<table id="tbl">
    <tr>
      <td>
        <select id="number1">
          <option>001</option>
          <option>002</option>
        </select>
      </td>
      <td>
        <input type="text" id="txt1">
      </td>
    </tr>
    <tr>
      <td>
        <select id="number2">
          <option>001</option>
          <option>002</option>
        </select>
      </td>
      <td>
        <input type="text" id="txt2">
      </td>
    </tr>
  </table>
  <button>
  test
  </button>

JavaScript

var tblData = document.getElementById("tbl");
document.querySelector('button').addEventListener('click', e => {
  let txtTbldata = '';
  for (var i = 0, rowlen = tblData.rows.length; i < rowlen; i++) {
    for (var j = 0, collen = tblData.rows[i].cells.length; j < collen; j++) {
      txtTbldata += tblData.rows[i].cells[j].children[0].value;
    }
  }
  alert(txtTbldata);
})