Passive tables - how to play?

Hiya!

I've got two related questions about passive tables in general.

What data do you need to classify a table as very passive, and how do you adjust your play to these tables?

Would it be OK to start limping in EP with stuff like Axs? Or is that just stupid?! I suppose that playing more drawing type hands in POS could be useful since passive opponents will let me draw on the cheap. But perhaps there is more to it?!

Also, sometimes I see posts where TABLES are labeled with "average VP$IP" and PFR numbers. Where do these come from? I know that PT will give these data for induvidual players, but how does it come about for tables? Is that done by finding a table where you have stats on ALL players, and averaging it out? Or is there any more direct way to that end?

I'm sorry, and I really suck. Also, I've got the stats to support that assessment...

Hopefully some solid advice here will help me suck less

/Zal3