JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr><td>A</td><td>B</td></tr>
    <tr><td>C</td><td>D</td></tr>
</table>

CSS

table {
    border-collapse: separate;
    border-spacing: 0;
}
table, td {
    border: 1px solid black;
    border-radius: 5px;
    -moz-border-radius: 5px;
    padding: 5px;
}