I didn't understand what you mean when you say "copies itself without needing to indicate the block number".
When adding the objects/blocks in the level, you can click on "grid setting" to configure the grid size. Then, you just need to drag with the mouse to add multiple copies of the block. You don't need to indicate any block number, just select the object type that you want (in the left panel) and click in the position in the level you want it to be created.
To make copy of an object, you can click on the object in the map, with the "select tool", and then click the "clone" button. Similar thing if you want to edit, or delete.
You can just ignore the list of objects in the right panel, if the map is very large, with hundreds or thousands of objects. It's easier to just click in the object in the map, to edit, delete or move the object.