While we might say "a collection of maps," "a set of maps," or "a series of maps," there's no single, specific term that captures the essence of multiple maps together.
If you're writing creatively, you could try using a more descriptive phrase, such as:
* A tapestry of maps
* A constellation of charts
* A cartographic symphony
Ultimately, the best collective noun for maps depends on the context and the desired effect.