Symbolism, Imagery, Allegory
It's got to be more than a little irritating if the guy you're seeing keeps showing you maps, like he's trying to educate you. That's what happens to Miranda.
For example, Dev brings Miranda an issue of The Economist to show her where Bengal and India are because he wants her to know where he comes from. Maybe you're thinking, "Oh, how sweet," but catch this: he also "[rolls] up the magazine, and [says], 'Nothing you'll ever need to worry about,' and he tap[s] her playfully on the head" (S 6) when Miranda asks a question about how to read the map. Kind of patronizing, no?
But maps don't only represent what Miranda doesn't know…they signify her willingness to learn (despite Dev); to bridge the gap between where she's from and this unfamiliar place called India (and the rest of the world).
When Dev tosses that issue of The Economist in the trash, Miranda takes the magazine out of the trash and studies the map to try and learn more about where Dev is from (S 7). That's something.