JSFiddle - React, Tailwind, and code Playground

HTML

<table id="tablee" cellspacing="0">
    <thead>
        <tr class="tablehead">
            <th>This</th>
            <th>is</th>
            <th>a</th>
            <th>table</th>
            <th>header</th>
            <th>and</th>
            <th>stuff</th>
            <th>though</th>
        </tr>
    </thead>
    <tr class="append">
        <td class="edit-column">asdf</td>
        <td class="edit-column">qwer</td>
        <td class="edit-column">zxcv</td>
        <td class="edit-column">rtyu</td>
        <td class="edit-column">tyui</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">wert</td>
    </tr>
    <tr class="append">
        <td class="edit-column">asdf</td>
        <td class="edit-column">qwer</td>
        <td class="edit-column">zxcv</td>
        <td class="edit-column">rtyu</td>
        <td class="edit-column">tyui</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">wert</td>
    </tr>
    <tr class="append">
        <td class="edit-column">asdf</td>
        <td class="edit-column">qwer</td>
        <td class="edit-column">zxcv</td>
        <td class="edit-column">rtyu</td>
        <td class="edit-column">tyui</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">wert</td>
    </tr>
    <tr class="append">
        <td class="edit-column">asdf</td>
        <td class="edit-column">qwer</td>
        <td class="edit-column">zxcv</td>
        <td class="edit-column">rtyu</td>
        <td class="edit-column">tyui</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">dfgh</td>
        <td class="edit-column">wert</td>
    </tr>
    <tr class="append">
        <td class="edit-column">asdf</td>
        <td class="edit-column">qwer</td>
        <td class="edit-column">zxcv</td>
        <td class="edit-column">rtyu</td>
        <td...

CSS

#tablee {
    width: 100%;
}

#tablee thead tr {
    background-color: #aaaaaa;
}

#tablee tr:nth-child(even) {
    background-color: #cccccc;
}

#tablee th,
#tablee td {
    text-align:left;
    border-bottom: 2px solid black;
}

JavaScript

$(function() {
    $('.add-column').click(function() {
        $('.append').append("<td class='edit-column'>iueo</td>");
        $('.tablehead').append("<th>Mo columns</th>");
    });
    
    $("#tablee").on('mouseenter', '.edit-column', function() {
        $(this).css('background-color', 'yellow');
    });
});