By default dwelling starts as soon as you indicate a cell and dwelling stops after the specified dwell time. After the dwell time has passed, the cell is selected. You can set the dwelling to stop on releasing the mouse. For example: with a dwell time of 2 seconds, the user must press and hold a cell for 2 seconds before the cell is selected.
Choose Tools > Mouse selection....
Select the option in the Start on press, stop on release option group.
Note: This option is only available if Dwell selection has been selected.