Show invisible characters in Numbers

Not according to the View menu, which does not include the Show invisibles/Hide invisibles menu item.

You can make returns visible by selecting the content of a Text box or of a cell.

You can also show the invisible characters in any text in Numbers by selecting and copying that text, then pasting it into a blank Pages document and choosing Show Invisibles in Pages' View menu.

I've not done any testing beyond those examples.

Regards,

Barry