Generation of more than one records in a single form entry

Generation of more than one records in a single form entry

We are trying to generate e-commerce application for bill collection.

Table-1 contains customer detail in 06 fields.
Table-2 contains bill detail in fields.

Now we want to generate one form having all these fields. It is simple.

But we want that customer data will remain as header data i.e. should be entered once and bill detail data can be entered more than once on a same form with total amount showing in the form at the bottom.

i.e. if one customer wants to enter his three phone bill detail at a time, he will enter customer fields one time but enter bill detail fields three times and then submit the form. This will actually generate one record in customer table and three records in bill detail table.

If it is possible, how?