What does Que tal si pruebas un sandwich de queso mean in English?

The phrase "Que tal si pruebas un sandwich de queso" in English means:

"How about you try a cheese sandwich?"

Let's break it down:

* Que tal si: This is a common way to suggest something, similar to "How about..." or "What about...".

* pruebas: Means "you try"

* un sandwich de queso: Literally "a cheese sandwich"

So, the entire phrase is a friendly suggestion to try a cheese sandwich.