drop down list (data validation) scrolling and searching
When opening the list, allow search-as-you-type in the list to choose from.
When the value is selected with single click, do not commit the change. Just close the list with the cell still in change mode. Let the user scroll up and down the values with keys or mouse-wheel and only commit after enter or another mouseclick.
Helman Frow commented
This is one of a gazillion legacy UX snafus that drives me up the wall. Google sheets gets these details right. Why can't Excel?