JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <colgroup>
        <col style="width:10px">
        <col style="width:20px">
        <col style="width:30px">
    </colgroup>
    <tr>
        <th colspan=100>
            numbers
    <tr>
        <td>1<td>2<td class="hide">3</td>
    <tr>
        <td>1<td>2<td class="hide">3</td>
    <tr>
        <th colspan=100>
            numbers
    <tr>
        <td>4<td>5<td class="hide">6</td>
</table>

CSS

td{
    border: 1px solid grey;
}
table {
    
    border: 1px solid black;
    border-collapse:collapse;
    table-layout: fixed;
}

tr th{
    background-color: #0caaaa;
}

JavaScript

els = document.getElementsByClassName("hide")
for(var i=0;i<els.length;i++)
    els[i].style.display = "none";