A mini schnauzer dog is a good small dog however they don't really make all that great of a lap dog.
Still some mini schnauzers may love to sit in your lap but usually not for a very long period of time.
My mom had a mini schnauzer who would sometimes lay in her lap and my lap and sleep or just lay there and like to be petted.
But then it would leave the lap and sometimes not want to sit in our laps for a few days.
The mini schnauzer dog breed is a good dog though and very loving and good around family and kids so if you're thinking of getting a mini schnauzer then I would recommend it.
Just be sure to give the mini schnauzer lots of love and attention and they will love you back as well.
But they don't make that good of a lap dog so if you're looking for a good lap dog then I would get some other type of dog such as a pug, Chihuahua, Maltese, Cavalier King Charles Spaniel and a Havanese dog.
Those dogs make some good lap dogs but a mini schnauzer does not however they will sit in your lap for awhile sometimes.