“How can I select something and start dragging and scroll down to find a place for it?”
If you drag and the mouse reaches within a threshold of the bottom of the screen, and if there are more rows, then the page will scroll slowly to show more rows.
Best practices
You generally shouldn’t have too much use for this feature since your pages should be relatively small. Ideally, you’d want each page to communicate immediately and visually. A sprawling page is usually a sign that the page has become a dumping ground for information, rather than a coherent set of ideas.
