Is it okay to leave a sleeping baby at home while you run out for a quick errand nearby?

NOT OK! Never ever leave the house without your baby even though they are sleeping. You never know when they will wake up suddenly. And if they happen to wake up the moment you just step out, nobody can imagine the harm they might cause to themselves. Eg. Covering the face with blanket or pillows and suffocate themselves, turning and fall off the bed ètc.