From The Document Foundation Wiki
How do I move a paragraph using the keyboard?
- put the cursor in the paragraph you want to move; and
- press Ctrl+Alt+↑ or Ctrl+Alt+↓ keys depending on the direction you wish to move the text.
- On macOS systems the ctrl has to be replaced with ⌘ Cmd
Note: On some systems, the Alt function is controlled by the window manager and the key combination doesn’t work.