JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>12&#x202F;345&#x202F;678</td>
        <td><pre>narrow no-break space</pre></td>
    </tr>
    <tr>
        <td>12345678</td>
        <td><pre>no space</pre></td>
    </tr>
        <tr>
        <td>12&#x200A;345&#x200A;678</td>
        <td><pre>hair space</pre></td>
    </tr>
    <tr>
        <td>12&thinsp;345&thinsp;678</td>
        <td><pre>thin space</pre></td>
    </tr>
    <tr>
        <td>12 345 678</td>
        <td><pre>space</pre></td>
    </tr>
    <tr>
        <td>12&nbsp;345&nbsp;678 </td>
        <td><pre>no-break space</pre></td>
    </tr>
</table>

CSS

body { font-family: system-ui; }
table, td, tr, pre {  border: 0; margin: 0;}