Multiple Item List

I wonder the technology behind holding data in one field
as a detail table

let me explain ..
think of Outlook personel's.
when you want to add an e mail address to a person
You click add email button and an e-mail address adding a list.

here . I think only one feild in the databese
and holding data as a detail table structure.

How can I design this kind of Item and How can I store this kind of informtion to the database...

Thank you for your interests...

perhaps if you have two tables

the field in the first table is an IDnumber
that is the same unique field in the second table

(the person's name, email address, etc. is in the second table)

is there any way doing this without usin second table..

(MAybe it seems to be a master detail. But behind the screen the structure is not master detail...)