The short answer? Your friend will have ZERO problems with that knife. For a longer explanation, see "Mnblade's fool-proof guide for tourists carrying a knife in Europe," below.
Mnblade's fool-proof guide for tourists carrying a knife in Europe:
* Leave the stillettos and balisongs and martial-arts-looking cutlery at home. Carry any sort of SAK (small or a larger locking model matters not; if you're worried, make sure it's a red-handled model - they're universally understood to be just a tool). Other options include Opinels or Lagouiles or a multi-tool. Likewise a traditional slipjoint. Frankly, I wouldn't even hesitate to travel around Europe with a knife along the lines of a Delica or Griptilian but would probably steer away from serrated edges.
* Look and dress somewhat normal (i.e. if you hair's dyed green and your face is pierced several times over, you might want to remove the eye- tongue- and nose-rings and wait until your natural color grows back before carrying a knife around Europe).
* Don't go breaking the law (if you're caught with drugs, or commit some heinous mortal sin like punching an organ grinder's monkey or chucking a beer bottle at rival soccer fans, the local cops will NOT care that your knife is only for cutting bread and salami). On the other hand, as long as you fit in and don't raise hell, no one's ever going to care if you have a knife in your pocket, period. If you need to prep some food, slice away. If you need to fix up your backpack, cut away. If you need to open a nice bottle of vino, corkscrew away.).
* If for some reason, you DO end up in a discussion with the local law (not very likely if you follow the first three guidelines), remain friendly, play dumb, and wave around a guidebook asking where the nearest MacDonald's is (even if -- God forbid -- you're IN a MacDonald's.
I'm American but lived on this side of the pond from 1993-98 and from 2003 until present. I've carried many different knives -- including a large SAK -- all over the place, using it openly when needed. NO ONE has ever raised an eyebrow.