Yes, there is a button in your top toolbar in EDOnline where you can lock the selected object on the page so it an no longer be accidentally moved.

That button can be found here:

When it is locked, the icon will change to a closed padlock icon land you will notice that the handles on the corners and edges of the object disappear. *Please note that the object still shows it is selected with a red outline.

To unlock the object again, just press the lock button so it changes back to the unlocked padlock icon and the handles reappear.