A scroll of taming tames tameable monsters nearby. Some monsters can resist. There is no difference between a blessed and uncursed scroll, but a cursed scroll will anger monsters instead of taming them.
Normally the scroll will affect only adjacent monsters, but if you are confused it will try to tame (or anger if cursed) every monster within 5 squares of your location (i.e. an 11×11 area). If you are engulfed, however, the scroll will only affect the monster engulfing you, even if you are confused.