Yes, a simple VGA splitter will work as you describe. Keep in mind that most VGA splitters will cause some quality loss on the VGA signal, meaning you may get some noite in your mapping projection.
Can you split 1 VGA to two monitors?
If your computer has only one VGA port, you can use a USB-to-VGA adapter to connect multiple monitors. The display works like any other plug-and-play monitor. The adapter even enables you to extend the desktop onto the second monitor. Purchase USB-to-VGA adapters at most electronics stores.