JSFiddle - React, Tailwind, and code Playground

HTML

<div id="scrolltable">
    <table>
        <tr><th><div>first col</div></th><th><div>second</div></th></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo foo foo foo foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar bar bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
        <tr><td>foo</td><td>bar</td></tr>
    </table>
</div>

CSS

#scrolltable { margin-top: 20px; height: 200px; overflow: auto; }
#scrolltable table { border-collapse: collapse; }
#scrolltable tr:nth-child(even) { background: #EEE; }
#scrolltable th div { position: absolute; margin-top: -20px; }