For some reason when you copy a full text block in Revit, after activating the text box and then selecting the text either by a. double-clicking and dragging or b. Ctrl+A, Revit adds a line-break to the end of the text on the clipboard. So then when you go to paste that text, either in Revit or some other software, the text gets pasted with a line-break at the end. Not a huge deal, but a very annoying bug when you have to copy/paste a few notes.
Interestingly when you copy paste text that has been selected by single-click and drag, Revit copies the text correctly with no bonus line break.