Can I ask you to think about why there is an import function? Maybe it's because different programs use different and mutually incompatible formats. So pasting in someone else's "phone book" is not going to work.

Thunderbird's native address book files have a .mab extension.

I suggest you persevere with the csv import.

http://xenos-email-notes.simplesite.com/417788922

You need to be aware that Thunderbird has a limit on the number of data categories, and you should try to remove any unused, empty or non-matching fields.

Some users prefer to work in the csv file directly, removing and rearranging columns to match Thunderbird's fields.

http://kb.mozillazine.org/Import_address_list_from_text_file

Thats a often asked question. and there is no good answer. If you downgrade to Version 31, or 24 or 17. It might work. The option was disabled in later versions because of bug-reports. The crashes that caused the disabling in the fist place commenced in V24. But not everyone who imported Outlook in V24 and 31 crashed.

Can't outlook export in .csv format? There are some freeware out there that might be helpful (be careful)

A .csv file can be imported. or a .vcf (I found Importing it into a spreadsheet, correcting it and reexport it as .csv was much easier than correcting inside Addressbook.)

With MoreFunctionsForAddressBook its easier to import.

EDIT didn't see that you got an answer.