I have a 64-bit Xeon with 8GB of RAM and I have created tables lareger the 4GB as a test ... to make completely sure ...
It says on this page (http://erlang.stacken.kth.se/faq/x1197.html) that "Dets uses 32 bit integers for file offsets" and "In practice your machine will slow to a crawl way before you reach this limit."
I have a 64-bit Xeon with 8GB of RAM and I have created tables lareger the 4GB as a test ... to make completely sure ...