http://www.appetise.com/restaurants?q=CV4+7ALApparently one in Earlsdon and one in Leamington (why the one in Leamington delivers to campus I don't know).
As for non takeaway a decent one is Noodle Bar in Coventry, which has massive portions and costs about £6,
There's also two all you can eat buffets in CovL
Cosmo in Coventry, which is a buffet, but can get expensive. ~£15 or so
Wing Wah in Tile Hill, another buffet, again a bit expensive. ~£14
In Leamington:
Been on Chandos Street, Leamington is a decent 'eat as much as you like' restaurant - you order and they bring the food to the table. Cheaper than the Coventry options and I personally think it's a better experience than the buffet style restaurant.
Oriental Star is another buffet, owned by the same people as Been.
Sabai Sabai is more expensive, but is a proper restaurant.