Certainly not in any numbers.
The smallest warp-capable vessel in use in any numbers is the Viper-class - and it's still nearly a kilometre long!
http://warhammer40k.wikia.com/wiki/Viper-class_Scout_Sloop
There are odd archeotech examples of small gunships and vessels being warp-capable, but this is the sort of thing that's only in the hands of the Officio Assassinorium or the Inquisition. certainly nothing a 'normal' citizen of the imperium - even a 'normal' starship captain - would even be aware existed, much less actually encounter.
There are smaller ships which aren't warp-capable, but obviously these are of limited use to most people.