It would likely be impossible to put one table view inside of another table view, and if you did manage to do it, it would be awful. Ask yourself, have you EVER seen this in a commercial app? If not, as a novice iOS developer, you are out of your depth trying to invent new UI paradigms.
Master the existing UI tools first. Don't try to use the UI elements in totally novel ways until you have a strong feel for the standard way to use them. Expect this to take 6 months or more.
Others have suggested a sectioned table view where initially only the first element of a section is visible, but when you tap on it, it expands to add other rows. This works quite well.
Another approach would be to use a master/detail UI, where tapping on one table view cell pushes a new view controller the uses a new table view to display detail information about the previously selected item. There are some use cases where you might have several levels of increasing detail.