In fact, the notion that PADI Enriched Air can still be learned with tables is news to me. When I took my nitrox course, I wasnt told that I could choose between tables or computer based. I was simply told that the course was computer based. I even asked about tables because the amount of actual knowledge in the manual seemed really low, and also because I took my OW in the time when computers seemed more the exception than the rule. In those days I was cautioned against computers and we dived tables.
But considering my teacher, who I take on his word (he is a very serious and safe diver and we are still in touch) I think it is possible that he might have been under this impression himself. I dont know where instructors get their info on this but I wouldnt be surprised to hear that it comes from the dive center.