Edit a cell, place cursor at the end F2
Paste values only ALT + ESV
Show in-cell drop down with previously entered value ALT + Down Arrow
Fills down value from cell above Ctrl + D
Add a comment or Edit comment Shift + 2
Insert new sheet Shift + F11
Insert Row Ctrl + +
Delete Row Ctrl + –
Copy Ctrl + C
Paste Ctrl + V
Cut Ctrl + X
Undo Ctrl + Z
Delete box (cell, row, column) ALT +ED
Insert box (cell, row, column) ALT + IE
Clear all contents ALT + EAA