expression
nice to meet you; pleased to make your acquaintance
A very formal, humble greeting used when meeting someone for the first time. It is a set phrase that literally means 'this is the first time I am meeting you' and is more polite than 初めまして.
お初にお目にかかります。私は田中と申します。
It is a pleasure to meet you. My name is Tanaka.
初めまして is the standard, neutral way to say 'nice to meet you'. お初にお目にかかります is a much more formal and humble expression, often used in business or very polite contexts.
A humble set phrase composed of お初 (first time), に (particle), お目にかかる (humble form of 会う, to meet). The expression literally means 'this is the first time I am meeting you'.