Data

Ctrl T
Convert the selected range into a Table Windows
Ctrl Shift ;
Insert the current time as a static value Windows
Ctrl ;
Insert today's date as a static value Windows
Ctrl Shift Space
Select the current region (or the whole sheet if pressed twice) Windows
Ctrl Space
Select the entire column Windows
Shift Space
Select the entire row Windows
Ctrl Shift L
Toggle filters on the selected header row Windows

Editing

Delete
Clear the contents of selected cells
Ctrl C
Copy Windows
Ctrl '
Copy the formula from the cell above Windows
Ctrl X
Cut Windows
F2
Edit the selected cell
Ctrl D
Fill down (copy the cell above) Windows
Ctrl V
Paste Windows
Ctrl Y
Redo Windows
Ctrl Z
Undo Windows

File & View

Shift F11
Insert a new worksheet Windows
Ctrl N
New workbook Windows
Ctrl P
Print Windows
Ctrl S
Save Windows
F12
Save As Windows

Formatting

Ctrl Shift $
Apply Currency format Windows
Ctrl Shift %
Apply Percentage format Windows
Ctrl B
Bold Windows
Ctrl 0
Hide selected columns Windows
Ctrl 9
Hide selected rows Windows
Ctrl I
Italic Windows
Ctrl 1
Open Format Cells dialog Windows
Ctrl U
Underline Windows
Ctrl Shift 0
Unhide columns Windows
Ctrl Shift 9
Unhide rows Windows

Formulas

Alt =
AutoSum Windows
Ctrl Shift Enter
Enter a legacy array formula Windows
F9
Recalculate all open workbooks Windows
F4
Repeat last action, or toggle absolute/relative cell references while editing a formula Windows
Ctrl `
Toggle showing formulas instead of their results Windows

Navigation

Ctrl Home
Jump to cell A1
Ctrl Arrow Key
Jump to the edge of the current data region
Ctrl End
Jump to the last used cell on the sheet
Enter
Move one cell down (or confirm entry and move down)
Tab
Move one cell right (or confirm entry and move right)
Ctrl F
Open Find
F5
Open Go To
Page Up / Page Down
Scroll up or down one screen
Ctrl Page Down
Switch to the next worksheet
Ctrl Page Up
Switch to the previous worksheet