First of all, I never had an iPhone in my hands so, my experience is based on transfer methods between two Android devices, not between Android and iPhone.
If you have questions to your iPhone, ask somebody who has one
What you need: Samba server on your tab and a file explorer on your iPhone with the possibility to map network resources.
Tethering: I belive Apple has a different name for this (I think Apple call it 'personal hotspot') however, just switch it on.
Than install a samba server on your tab and create a share. Finally, connect your tab to your 'personal hotspot' and note the IP address. Start the samba server within the share.
Install a file explorer on your iPhone and map the share.
But keep in mind: This method is very fast, but very very power consuming. If I say very, I mean very.
Bluetooth: Just switch it in on both devices, connect them and send the data you wish. But depending on how huge the files are, it can take hours until it has finished.
I hope that helps
Sent from my A510