JSFiddle - React, Tailwind, and code Playground

HTML

<div class="colorir">
  <h2>Este é o titulo que pretendo esticar até ao fim da tabela</h2>
</div>
<br>
<table>
  <thead>
    <tr>
      <th>One</th>
      <th>Two</th>
      <th>Three</th>
      <th>Four</th>
      <th>Five</th>
      <th>Six</th>
      <th>Seven</th>
      <th>Eight</th>
      <th>One</th>
      <th>Two</th>
      <th>Three</th>
      <th>Four</th>
      <th>Five</th>
      <th>Six</th>
      <th>Seven</th>
      <th>Eight</th>
      <th>One</th>
      <th>Two</th>
      <th>Three</th>
      <th>Four</th>
      <th>Five</th>
      <th>Six</th>
      <th>Seven</th>
      <th>Eight</th>

    </tr>
  </thead>

  <tbody>
    <tr>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
    </tr>
    <tr>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
    </tr>
    <tr>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
      <td>One</td>
      <td>Two</td>
      <td>Three</td>
      <td>Four</td>
      <td>Five</td>
      <td>Six</td>
      <td>Seven</td>
      <td>Eight</td>
      <td>One</td>
     ...

CSS

.colorir{
    padding: 5px;
    background: #003686;
    color: white;