Tab / Shift + Tab : Navigate columns

Arrow Keys : Move cell selection

Enter : Complete cell entry

Double Click : Edit selected cell

Click & Drag : Select range of cells

Ctrl + C / Ctrl + V : Copy/Paste

Supported Formulas:

=SUM(A1:A5), =AVERAGE(A1:B3)

=COUNT(A1:A5), =MIN(A1:A5), =MAX(A1:A5)

=A1*C2, =A1+B2-10