You can select multiple BPMN elements from the Graph Canvas Area and move them to another location in the Graph Canvas. Multiple BPMN elements can be selected with the combination of left mouse click and <CTRL> key or drawing selection rectangle on the activities with the help of Activate the lasso tool elements from Toggle Palette.
A selection rectangle is a virtual rectangle drawn when you select Activate the lasso tool element from Toggle Palette and press right mouse button to drag over the activities. On release of mouse button, the rectangle becomes invisible and the activities inside drawn rectangle are selected. An example of multiple selections is displayed below.
Multiple activities can be deleted by selecting multiple activities on the canvas and press <Delete> key from the keyboard.