1. You data page is not getting populated here. If the data page is Source, then it should have pxresults. So you need to copy the data from User Page you have in your acitivity to data page or use Report definition as a Source
2. As Surya mentioned, your UI is wrong. You need to use Table or a grid as below:
It's problem with your UI(Repeating Dynamic Layout expects Section). If your expecting data table data to be in a table grid format just make a change as Table instead of Repeating Dynamic Layout and as a best practice make datapage source as default existed DataTableEditorReport to fetch the entire data table list.