Highlight at least two tasks: the task from which you are copying resources and the task to which the resources will be copied. Be sure that the last task that you highlight contains the resources that you want to copy.
Right-click on the resource(s) that you want to populate; click on Copy Selected Resources to Tasks.
Note: This option will appear only if more than one task is highlighted.
The Select Task dialog will appear. Highlight the task(s) to which you want to copy the selected resources and click Select.
The selected resource(s) will now be copied to the selected task(s). This may help speed the data entry process of copying multiple resources to multiple tasks.