I have spent a great deal of time in the last week as a visitor in the hospital at Poitiers. I have noticed that some rooms are marked (for example) Office Alimentaire while others are Bureau de Soignants.
So when is a bureau an office, and when is an office a bureau?
(edit following @Mark 's contribution)
And where does Cabinet fit into all this?
Well one is the supply pantry or store and the other is the Nurses office. For me bureau and office are the same thing only the pre- or suffix changes the use.
And when do they become a "cabinet "?
When there are numerous medical facilities under one roof.
Knowing a little French, I suspect that there is a subtle distinction between them. But thank you so much for translating Alimentaire and Soignants 
Not necessarily, my dentist (when I had one 
) had a cabinet of just him.
Mark, just my take on it. Not set in stone.
Cabinet is where you receive clients or patients if you are a Dr or avocat etc. But notaires have études where they may or may not receive clients.
An office is a pantry for keeping and /or preparing things including things like coffee, or where the big ugly ice cube machine lives in a bar, and for cleaning stuff, your bureau is for writing or doing business or commerce.
Vero, thanks for the clarification. I was on the right track then.
And I was worrying about what would enlighten me today 
Thanks @vero - another distinction to add to the brain cells. Just off to let my partner know (and to add Office" to my faux ami list 
)
Just to add to the confusion, an étude de notaire is sometimes called an office notarial, it’s a nice distinction though and off the top of my head I don’t know why it exists, maybe it’s a regionalism.
Well thank you very much! My state of confusion returns…
It’s not regional. There are some who like to call it an etude. Mostly those who work there. Then others who say office notarial. Having worked in one I asked the question and from what I can perceive etude sounds a bit better professionally? But hey I’m not French subtleties can pass me by …… as ever 
My notaire in town has an an étude but her offshoot branch in a much smaller town is called an office notarial, so I wonder if it is just more hands-on with no separate archives etc. She was president of the regional notaires so I don’t think it is necessarily a prestige or smartness thing.
Where I come from on the Côte d’Azur I was only ever aware of études, but here in Aquitaine I see both étude and office notarial are used.
My friends who are notaires say ‘passe me voir à l’étude si t’es en ville’.
You are right I reckon. The first main place is the etude. I, too, came across this in Nouvelle Aquitaine. Maybe it is regional after all? Our French neighbours from the south were surprised by this
I have just returned from the Notary, she said it is an etude.
to me “d’office” is auxiliary/backup or utility type thing. almost for dépannage/backup or to be brought in temporarily if the thing/ person normally there or used, fails or is not there for some reason… Couteau d’office is utility knife.
So for all these reasons I’d expect a room with an “Office” word in the sign on it to be some sort of utility type room. (though utility room is buanderie ahem).
I think Office notarial goes back to an older usage meaning ‘official’ as in ‘here we do official services’.
Isn’t that only if it’s used for laundry? (That’s a question, and not a rhetorical one!)
I assumed it was derived from the Latin Officium, with a sense of necessary, duty, ceremony or courtesy etc.