Additional line for addresses should appear in the contact card
When entering someones address you should allow for a second and third line for things like a suite, apartment or office (the same way you do in Outlook for Windows).
Quentin King commented
I agree the address layout is simply not good enough. Also we need the ability to printout address labels. The address book is a crucial part of the outlook system but needs to be updated. These are not difficult changes and should the work of an hour or so for the software engineers.