Contour layer added automatically

I am a rank amateur CAD guy.  I have the electronic components and electrical libraries loaded.  When I first set up my drawing surface, I create a layer for wiring and another for components.  As soon as I insert the first component on the component layer, a new layer called contour is created automatically.

When I delete the layer Contour, I warned that all work will be deleted with it.  When I delete the layer, the component disappears.  But the component layer stays.

When I repeat the process, but delete the Components layer instead, I again get the warning that all my work will be deleted.  And when I delete Component layer, the component goes away. This time leaving the Contour layer.

Is this normal?  Am I supposed to use the Contour layer with electrical/electronic drawings and forget doing wiring and component layers?

You might have a look at the Blocks section in the manual:
https://docs.librecad.org/en/latest/guides/blocks.html

The libraries are contributions from other users and they may not have followed the intended block functionality. They can also be very different, if they were built by different contributors.

So what you describe is intended by blocks design. Probably the component library is built with entities on layer contour.

When you add a component, all layers from the block are imported too, and the block entities keeps these layers.
What you add to the components layer is called an INSERT, namely a reference to the block.
Means the block is owned by components layer and the block entities stay on the contour layer.
No matter which layer you delete, the added component disappear and the other layer becomes empty.
You can elaborate with contour layer properties, e.g. when you change the color of the contour layer, the component will change its color too. Provided the block entities use By Layer or By Block in attributes.

The solutions are to live with the additional layer or to modify the blocks in the library to your own needs.
If you keep the contour layer, the components will react to the components layer too, because the insert is on the components layer.

If you work on schematics, you might have a look at KiCad EDA, which is specialized for this kind of tasks and is as free as LibreCAD too.