JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="myInput" onkeyup="myFunction()" placeholder="Search for names..">
<section>
  <h2>Таблица 1</h2>
  <table>
    <tr class="header">
      <th style="width:60%;">Name</th>
      <th style="width:40%;">Country</th>
    </tr>
    <tr>
      <td>Alfreds Futterkiste</td>
      <td>Germany</td>
    </tr>
    <tr>
      <td>Berglunds snabbkop</td>
      <td>Sweden</td>
    </tr>
    <tr>
      <td>Island Trading</td>
      <td>UK</td>
    </tr>
    <tr>
      <td>Koniglich Essen</td>
      <td>Germany</td>
    </tr>
  </table>
</section>
<section>
  <h2>Таблица 2</h2>
  <table>
    <tr class="header">
      <th style="width:60%;">Name</th>
      <th style="width:40%;">Country</th>
    </tr>
    <tr>
      <td>Alfreds Futterkiste</td>
      <td>Germany</td>
    </tr>
    <tr>
      <td>Berglunds snabbkop</td>
      <td>Sweden</td>
    </tr>
    <tr>
      <td>Island Trading</td>
      <td>UK</td>
    </tr>
    <tr>
      <td>Koniglich Essen</td>
      <td>Germany</td>
    </tr>
  </table>
</section>
<section>
  <h2>Таблица 3</h2>
  <table>
    <tr class="header">
      <th style="width:60%;">Name</th>
      <th style="width:40%;">Country</th>
    </tr>
    <tr>
      <td>Alfreds Futterkiste</td>
      <td>Germany</td>
    </tr>
    <tr>
      <td>Berglunds snabbkop</td>
      <td>Sweden</td>
    </tr>
    <tr>
      <td>Island Trading</td>
      <td>UK</td>
    </tr>
    <tr>
      <td>Koniglich Essen</td>
      <td>Germany</td>
    </tr>
  </table>
</section>

JavaScript

var table = document.querySelectorAll("table");
for(var i = 0; i < table.length; i++) {
	console.log(table[i].rows)
}