Hi,
The "pack generator" is the generator which will be use when a serial should be generated.
You don't have to populate your database with serials, they could be generated dynamically when needed (when an order is confirmed for example).
You can use "regular" generators like the "random" one and populate the database, or use any generator and let the system make his stuff when required. The database will grow dynamically with orders.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.