If your pagan neighbor invites you to his home for a meal, then eat what is set before you without asking any questions. In this situation you should abstain from eating the meat. You should seek to build up the weak brother who is unsure about these things, and you should make a statement by your actions that you do not share the table of demons. We live in a culture where most primitive forms of idolatry have seemed to fade away. But this is only an illusion.
Paganism is still alive and well in our modern world.
It has adapted to our highly educated, high tech economy. Many forms of animism is still prevalent in our world. Furthermore, the advanced our society does not mean that demons have become obsolete or irrelevant.