What you are experiencing occurs because screen views are browser renderings of HTML code, so the HTML tags do not show. But they are still there. When you copy for a batch update or export, you also copy the tags that are invisible in a screen view. And those are pasted into a spreadsheet. But the spreadsheet is not rendering HTML, it is interpreting the HTML tags as text. Your spreadsheet may have the ability to paste as HTML. If it does not, you will need to use other editing features to eliminate the tags. Typically, spreadsheets use other methods to record line breaks within cells.
