JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr><th>1</th><th>2</th><th>3</th></tr>
    <tr><td>lalala</td><td><textarea id="t"></textarea></td><td>oi</td></tr>
        <tr><td>lalala</td><td>aaaaaaaaaaaaaa</td><td>oi</td></tr>
</table>
<input type="button" value="Mess with table" id="mess" />

CSS

th, td {
    border: 3px solid black;
}

/* The property below does the trick */
textarea {
    width: 100%;
    resize: none;
    display:table-cell;
}

JavaScript

function mess() {
    $('table').append('<tr><td>lalala</td><td>aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</td><td>oi</td></tr>');
}

($('#mess').click(mess));