I can't remember how I learned how to do this, but I'm 90% sure it's a built-in default shortcut for Mac Excel 2011.
Make a selection in your spreadsheet. Hit
option-tab to move that selection to the right,
option-shift-tab to move it to the left,
option-return to move it down, and
option-shift-return to move it up.
I can't find any documentation of this shortcut to know what it is called, so I could look up the Windows Excel 2010 equivalent. Does anyone know what this is called?
Edit: I noticed today that this can actually be used to enter data into all of the selected cells. In other words, you select some cells, start typing the data you want, and then
option-return to apply that data to all of the selected cells and select the next empty set of cells. Using
enter instead of
return will result in the data simple being entered into all cells without selecting the next group. So it appears as though the equivalent would be for something like "enter into all selected cells".