Some of you may have seen this feature in Excel, where you have the ability to quickly fill rows with same information. I am finding on my personal SharePoint task list that waiting for SharePoint to complete the “Assigned to” field is somewhat cumbersome, since I’m the only one who is ever assigned tasks on my own SharePoint task list. Luckily, SharePoint Online has that same feature in DATASHEET view. You see this datasheet view when you choose Quick Edit if it’s available for your list.
Do you see that little blue square at the bottom of this cell?
When you place your mouse over it, it turns into a cross hair, and you can drag it down as many cells as you need.
It will then copy and paste the information from the first cell into the cells below, as shown.