override func numberOfSections(in tableView: UITableView) -> Int {
    // You need to return minimum one to show the cell inside the tableview
    return 1
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // return the number of rows inside the tableview.
    return 3
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) 
// identifier string should be same as what you have entered in the cell Attribute inspector -> identifier (see the image).

    // Configure the cell...
    cell.textLabel?.text = "Cell \\(indexPath.row) :" + "Hello"
//cell have different style Custom, basic, right detail, left detail, subtitle.
//For custom you can use your own objects and constrains, for other styles all
//is ready just select according to your design. (see the image for changing the style) 

    return cell
}

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        // this delegate method will trigger when you click a cell
}