Update multiple cells at once: select two or more cells, type an entry in the first cell, and then press Ctrl-Enter.
Tag: Keyboard shortcut
Double-click fill handle to copy current cell down, stops at the first blank in adjacent column. Or select cells & press Ctrl-D.
Press Ctrl-Shift-! to apply the Number format, e.g. 1,234.56, to one or more cells that you've selected.
Press Ctrl-Shift-_ (underscore) to remove borders from a cell.
Press Alt-Down Arrow to get an in-cell drop-down list of adjacent entries in the current column
Press Ctrl-0 (zero) to hide a column. Use the F5 key to navigate to a hidden column and then press Ctrl-Shift-0 (zero) to unhide.
Press Ctrl-Tab to switch between open workbooks. Use Ctrl-Page Up/Ctrl-Page Down to switch between worksheets.
Press Ctrl-+ (the plus sign on your keypad) to add rows or columns, use Ctrl-Minus (the – sign on your keypad) to delete.