How do I transfer an eBook from my computer to a AGPTek Android Tablet

[Cofresi]

I am using Windows 7 64Bits Ultimate and I want to transfer a few eBooks from my computer to my new tablet...I connect the tablet to the computer using the OTG Cable but the computer does not assigns a drive letter to the tablet..What am I doing wrong....Any and all help will be deep ly appreciated....TIA