You can edit multiple records simultaneously. To do this:
In the List View, select the records you want to edit and click on Edit.
You can also select multiple cells in the List View using keyboard shortcuts.
Use Shift + Left Click to select a range of cells or Ctrl + Left Click to select an individual cell.
A dialog will open notifying you how many records you will be editing.
Select the Field you want to update
If you selected multiple cells using keyboard shortcuts, the Field to update will be automatically selected.
Enter the new value for that Field
In some cases, there will be additional options. For example, for List Fields, you need to choose if the new values will replace or be added to existing values.
Save and the records will be updated.
Type above and the results will be displayed here.