Multi field/object in Custom form

[#1]

We need to include a multi field in a custom form, so that user is able to choose number of fields needed of same type.

For ex: while filling a custom form, user might want to add 5 product part numbers(each of text field). In another case, user might want to add 10 product part numbers.

Multi-field can have a '+' and '-' options to add more fields and remove existing field respectively.

Can we also create a multi-field of objects? This will help users to add multiple objects in custom form. This could also be similar to "Risks" and "Expenses" in Projects currently.

Ex: Below is an Product object with following fields:

Part number

Description

Price

[#2]

This could be very helpful if we want to track additional data in multi-field format at project level.

It might not be effective to include multiple text(or any other) fields in custom form, if you are not aware how many such fields would be filled by the user.