Trying to Built Pricing Object in MDG

I want to build Custom Object for Pricing.

I am doing it for one pricing condition and access sequence combination at this point of time.

I used standard UIBB that are available in  FPM form and list component. It used standard class cl_usmd_entity_value2_proxy.

Right now i was stuck at entering data into list. It does not allow me to enter data.

Can any body guide me step by step what i have to do in order to add data into list ( Multiple records) and submit the record. There is add delete option in tool bar schema but i guess i need to write a code for that event.

Regards

Siva