adding more rows and data

hi guys

here is my problem

i know to make table from html

but i really want to add more rows and data from css ... , and i dont know how to do that ..

because iam using c# to make a project  and i want to add more rows and data when the customer press (add) button

here (c# code)

mytable.style.add("???","???") ... i dont know what should i write here so i can add more rows and data ...

i hope you guys can help me

thank you