What Is the About:Blank Page in Web Browsers For?
It is simply a blank page that is built into some web browsers. Some people just like to have a blank page rather than see/load anything else when they start their web browser or open a new tab/page.
The about URI scheme is designated for internal web browser use. It originated in Netscape Navigator, the web browser that gave rise to Mozilla Firefox. This includes about:blank. Per IETF RFC 6694, about:blank is reserved for a blank page. Essentially, every web browser that supports about implements about:blank and it is pretty much the same everywhere. Because about:blank is little more than a blank internal page, it does not depend on any external resources and serves as a good default on metered connections or slow systems.