When I needed space at the top of a OneNote page that already had a bunch of notes I used to go through the pain of moving each note around to create more space. However, today I found this cool menu option under the “Insert” menu option called “Extra Writing space”. Use that to insert or reduce space between your notes.
Choose the menu option and move your mouse over your page. You will see either a horizontal or a vertical line appear depending on the location of the mouse cursor over the page. Left-click the mouse button, hold and drag appropriately to add or reduce space on the page. If you perform this operation in the middle of a note I noticed it splits the note into two.