It is. You could add a Custom link with its url set to '#' and add sub menu items to it (remember, when adding sub menu items, you need to drag them underneath their parent). The sub menu items would be Content Menu Items so that you can point them to the
corresponding Product content item.
OK I tried this but it seems to render oddly - unfortunately I can't post an image here to show you.
It seems to work but I see new space allocated under the main menu (like a second empty menu area, same size/shape as main one) and a vertical line in that that is positioned at the end of the new sub menu item - these lines are visible and ugly and appear
even when I do not select any menu or sub menu item.
The theme I'm using is Contoso and basically it renders ugly - must I use some special/advanced menu component or something to do this better?