Hey Henry,
Just call a microflow with the click of a button and then in the microflow, first, retrieve the list from the database and then create use a change list activity to add the data in the list.
Creating the object is totally up to you, you can either use a form to take input or create it yourself,
after the whole thing is done, just refresh the page or show it again,
Hope it helps!
Use the Microflow action by the onclick event of the button.
In that microflow, you can create a new object and add it to the list.
Be aware that when commiting the object, you need to set ‘refresh in client’