How to display database data in a repeater group?

Hello everyone, I have a custom state that is using arbitrary text to save data from 4 inputs as shown in the image below.

What is the best way to save this data in my database to display in another repeater group after being registered. each item on its separate line?

Reason for the question: The ways I have already tried save all the data in a single line of text, where I find it difficult to display in another repeating group later

Depending on the database model, I suggest that each of the individual fields becomes a database field in a database entry. This also makes the output in a repeating group much easier.

In a contact form, for example, the name, e-mail, subject and text would all be a database field (column) within a single database entry (row) in the “Leads” database.

Can you help me how can I do this?

There are 4 pieces of information that I take through the inputs and store in a custom state

1- quantity of the piece;
2- description;
3- unit value;
4- subtotal

How can I organize my database to save this data separately and then display it in a repeating group?