JSFiddle - React, Tailwind, and code Playground

HTML

<div class="relative">
    <div class="table">
        <table>
            <thead><tr><th>col 1</th><th>Col 2</th></tr></thead>
            <tbody>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
                <tr><td>sweet</td><td>tooth</td></tr>
             ...

CSS

.relative {
    position:relative;   
}
.table {
    margin-top:18px;
    max-height:400px;
    overflow:auto;
}
thead {
    position:absolute;
    top: -18px;
}