JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>
<style>
table, th, td {
  border: 1px solid black;
}
</style>
</head>
<body>

<h1>Add Specific Width to th</h1>

<table style="width:100%">
  <tr>
    <th style="width:30%">One</th>
    <th style="width:70%">Two</th>
  </tr>
  <tr>
    <td>30%</td>
    <td>70%</td>
  </tr>
</table>

</body>
</html>