Here is Extjs Copy paste grid, It work for Extjs 3 and Extjs 4
This example shows how to create a Excel grid with inline editing.
Selecting Cell range (1st method): shift + UP/DOWN/RIGHT/LEFT key
Selecting Cell range (2nd method): shift + mouse down
Selecting Cell range (3rd method): Mouse down + Mouse drag
Copy selected cell to clip board: ctrl+c
Paste selected cell to grid/excell sheet: ctrl+v
You can see demo and download Extjs copy paste grid excel grid here