JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr><td class="comment">Fooasdasda<br />sdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasd</td><td class="comment">Fooasdasda<br />sdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasd</td><td class="comment">Fooasdasda<br />sdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasd</td></tr>
    <tr><td class="comment">Fooasdasda<br />sdasdasda<br />asdasdasdasdsdasdasdasdasd</td><td class="comment">Fooasdasda<br />sdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasd</td><td class="comment">Fooasdasda<br />sdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasdsdasdasdasdasd</td></tr>
</table>

CSS

* { margin: 0; padding: 0;}
td { border: 1px solid black; position: relative; }
.comment:after {
    content: "";
    position: absolute;
    left: calc(100% - 0.5em);
    top: 0;
    border-left: 0.5em solid transparent;
    border-top: 0.5em solid red;
}