The people of Book include both Jews and Christians, which many of them were blasphemers at the time of these Noble Verses. So the food of the people of the Book is allowed. I personally eat from American restaurants here in the US. Most of my food is halal Muslim food, but I sometimes also eat from big franchise restaurants, because they're owned and operated by Christians and Jews.
We don't eat pagans' food. Food prepared for idols or in the name of idols we don't eat from at all. However, the Jews' and Christians' food, we recite the Basmala before we eat it. We do this with all food, regardless. We of course don't eat any pork product (sausage, bacon, ham, etc...).
Personally, when I shop for meat, I go for Halal or Kosher, since they're both bloodless and have the Holy Name of GOD Almighty recited over them at the time of slaughter. But sometimes we also buy deli meat from regular American stores. And when we go to restaurants, we eat any non-pork food if the restaurant is owned by Jews or Christians.