JSFiddle - React, Tailwind, and code Playground

HTML

<form name="tablegen">
  <label> Rows:
    < input type="text" name="rows" id="rows" />
    < /label>
      <br />
      < label> Cols:
        < input type="text" name="cols" id="cols" />
        < /label>
          <br/>
          < input name="generate" type="button" value="Create Table!" onclick='createTable();' />
          < /form>

            < div id="wrapper">
              < /div>

JavaScript

function createTable() {
  var num_rows = document.getElementById('rows').value;
  var num_cols = document.getElementById('cols').value;
  var theader = '<table border="1">\n';
  var tbody = '';

  for (var i = 0; i < num_rows; i++) {
    tbody += '<tr>';
    for (var j = 0; j < num_cols; j++) {
      tbody += '<td>';
      tbody += 'Cell ' + i + ',' + j;
      tbody += '</td>'
    }
    tbody += '</tr>\n';
  }
  var tfooter = '</table>';
  document.getElementById('wrapper').innerHTML = theader + tbody + tfooter;
}