A text object in Photopaint can be used as a container for anything else than typed text.
The most useful thing might be pasted vector files which maintain their sharpness, no matter whether you resize them. But also pasted bitmaps in text objects maintain their original resolution.
Though the assign button is pressed the new created object does not apply a definite change, unlike to a "usual" object layer.
But: Any adjustment or effect gets lost if you resize the new text object again, so you should use lenses on the new text object to make adjustments or applying effects on that object.