Exceljet

Quick, clean, and to the point

Extend the selection to the last cell up

Windows shortcut 
CtrlShift
Mac shortcut 

If the active cell is empty, Excel will extend the selection to the first non-empty cell above the active cell. If the active cell is non-empty, Excel will extend the selection on the last non-empty cell above the active cell. On a Mac, the command key (⌘) can be used instead of the control key.