What is the meaning of 'Don’t get me started.'
These lines are from sitcom Friends.
Fyi, I put some more lines below.

Alice: (laughs) No. No. No. (Sits down.) Okay, now, see, I wanna name the girl baby Leslie, and Frank wants to name one of the boy babies Frank JR. JR.
Chandler: Wouldn’t that be Frank the III?
Alice: Don’t get me started.

Question

What is the meaning of 'Don’t get me started.'
These lines are  from sitcom Friends.
Fyi, I put some more lines below.

Alice: (laughs) No. No. No. (Sits down.) Okay, now, see, I wanna name the girl baby Leslie, and Frank wants to name one of the boy babies Frank JR. JR. 
Chandler: Wouldn’t that be Frank the III? 
Alice: Don’t get me started.

Answer

Often when one has a large amount of things (mainly negative) to say about a particular topic, this idiom is used.

Example:
Don't get me started on why I can't stand him.

Answer

Aly is right; I'm just going into more detail.  
When someone says, "Don't get me started," it is usually a mock warning.  The expression suggests that they have sooo much to say about a particular subject, you don't really want to listen to all that they have to say about it.

Ne manquez pas cette occasion d'apprendre une langue depuis chez vous. Découvrez notre sélection de professeurs de langues expérimentés et inscrivez-vous dès maintenant à votre premier cours !