Yes, I've flown Business Class twice on TAM in the last 6 weeks from Asuncion to Sao Paulo. There is a TAM business class lounge, through the door of the duty free shop. However, it is pretty basic with uncomfortable seats and just snacks. It is an airless (window-less?) room. I was there both times at about 10 in the morning and it was unattended both times. If you have a short wait, then the better option is the snack bar you can see over to your left as you approach the duty free shop. It has much better seating, the service is good and the food is fine. I left the lounge on both occasions to sit there instead with a nice view over the runway.