The "TELUS Flex Data Plan for Tablets" appears to be a grandfathered plan. There were 2 different releases of this plan. The details below are only accurate if your Flex Data Plan was added after April 02, 2014.
Please Note: Your device must be programmed with APN = isp.telus.com; if any other APN is used (e.g. sp.telus.com) then all data is charged Pay Per Use rates.