While in a Pakistani household

Pakistani locals pride themselves for being very hospitable and refusing their offerings can be considered rude.  Upon entering, you may be offered tea and sweets.  You don't have to eat the whole bunch, just have a bite or two, and never forget to praise the food.  Note that you should always use your right hand when taking in food.  The left hand is inauspicious for the Pakistani, as does in some Asian countries.

Finishing a Pakistani meal may require a fine balance.  Leave too much food and they may interpret it as lack of concern for the meal; leave none and more will be served for you.  What you can do is to leave just a few morsels and declare that you're full, and then praise the food as well as your host.