Line breaks in table cells not rendering/glitching

[redpandamonium]

Inserting a <br> element into a table cell does not display in the editor. It's a bit glitchy and ultimately doesn't display.
Ideally it would line break correctly. But as a smaller target I think not rendering it, but fixing the graphical glitches, is a viable solution.

[GetoXs]

The same

Editor doesn't handle br tags correctly.