@Sai all the tools available on the dashboard is accessible via the blue triangle on the grid.
For example: Copy Across is available via Edit - Copy Across, etc.
There is no Undo in Anaplan. If the user wants to know what was the previous value in the input cell, they can do right-click and View History to check the previous input. They can either re-input the value or Copy (Ctrl C) and Paste (Ctrl V) the value into the cell again.