The Pac-Man games have a large border around the play area, making the play area small, some smaller than others.
Pac-man Battle Royale for instance has an annoyingly small play area.

Let's fix that!

In order to maximize the play area we'll use the Windows Magnifier which is installed on Windows by default.

Confuring the Windows Magnifier app:
Windows logo key + Plus sign (+)  to start the magnifier app.
Click the cog wheel and go to settings.
Change the "Zoom Step" to something low (e.g. 5% or 10%) in order to have better control of the zoom level.
Optional: Disable "Edge smoothing" as it doesn't work well on all zoom levels.
Optional: Disable follow mouse

Keyboard shortcuts to zoom in and out:
Windows logo key + Plus sign (+) zooms in.
Windows logo key + Minus sign (-) zooms out.

Getting the zoom centered:
When zooming in with the keyboard shortcuts, it zooms in on where the mouse is. Conveniently the game centers the mouse automatically when the game starts. If you have moved your mouse after starting the game the zoom will not be centered. Re-center the mouse by Alt+ Tab to another application and Alt+ Tab back to the game. Zoom out all the way and zoom in again. The zoom should now be centered.

Enjoy!

The border around Pac-man Battle Royale has been removed in Pac-man Museum+, so it's possible to buy that and get a better experience:
https://steamproxy.net/steamstore/app/1665130/PACMAN_MUSEUM/
There's no discount for Pac-Man Museum owners though.