But if you wanted to, the only way I can think of would be to inherit the
TabPage class, and mark it with a ToolBoxItem(True) attribute. However, I am
not sure how useful it would be.
Attributes are not the same thing as properties. You need to look up
attributes, in particular the toolboxitem attribute.
It won't help you, because even though you'll be able to drag onto the
screen and customize it - how are you going to add it to a particular
tabcontrol? The tab control designer doesn't let you add existing tab pages
you have defined someplace - it will just add new ones.