Is Greek Street in London a safe and desirable place for dinner?

It is one of the best known restaurants in London. http://www.lescargotrestaurant.co.uk/Lescargot/HOME.html Greek St runs between Soho Square and Shaftsbury Avenue, the area is full of cafes, bistros and restos and you will be fine.

Agree, it's safe and busy.
S

Without wishing to spook OP I'd put the emphasis on busy, particularly around theatre time. There can be the occasional pick pockets in Soho and the theatre crowd can look quite posh so occasionally can become targets of those looking for money. I always take usual precautions in London, especially in Soho. I'm there (Soho, including Greek Street - not L'Escargot which I have never patronised) for lunch usually, or to get cannolis from Sicily at I. Camisa in Old Compton Street. The problem with Soho, if you are not prepared, is the quantity of pedestrians ratio to the narrowness of the pavements. It can be quite a jostle, particularly on Wardour Street and Old Compton Street. If I were there all dolled up at theatre time I'd have a moneybelt.