Is it ok to rest a 7.39 kg monitor on a ps4?

Nope.

It's not advised but it won't necessarily kill the PS4. Over time it will definitely strain it and could well damage the disc reader inside (e.g. Bend it)

If your PS4 is on a table then I suggest either move it to the side or put it on the floor under the table where you won't tread on it, just to be safe really.

No, it's not designed to have anything that heavy standing right on top of it.