Importing phone/fax/mobile phone numbers from CSV.....best practices?
I'm assuming that home and work are location types in your Civi?  If that is in fact the case, the one question I would ask from what you included is what location type to assign to the mobile phone.  Home and work would be location types, and phone type would be phone, mobile, or fax.  You would then set up your mapping in the contact import to assign the correct location and phone types to each column. Here is a sample of what I mean: 



(I chose home as the location type for the mobile but that might not be correct in your situation.)

Hope this helps,
Lesley