When you have too many floating objects in a layer, they may prevent you from accessing or editing other parts of the image, because you keep accidentally clicking on and selecting the floating objects. To avoid this, you can apply a floating object to the layer to lock it down permanently and get it out of the way.
Applying an Object to the Image
When a floating object is selected (showing “marching ants” on the border), right click on the object and choose Apply to Image from the menu. You can also use this command from the Layer Objects sub menu of the Layers menu under Image.