JavaFX popular TableView com uma List

Se for pra variar o numero de colunas veja esse exemplo

Nesse caso mudar os valores dessas variaveis dentro do programa e veja o que acontece

private static final int N_COLS = 5;

private static final int N_ROWS = 1000;

import javafx.application.Application;
import javafx.beans.property.ReadOnlyObjectWrapper;
import javafx.collections.*;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.stage.Stage;

import java.util.*;

public class DynamicTableView extends Application {    
    private static final int N_COLS = 5;
    private static final int N_ROWS = 1000;

    public void start(Stage stage) throws Exception {
        TestDataGenerator dataGenerator = new TestDataGenerator();

        TableView<ObservableList<String>> tableView = new TableView<>();

        // add columns
        List<String> columnNames = dataGenerator.getNext(N_COLS);
        for (int i = 0; i < columnNames.size(); i++) {
            final int finalIdx = i;
            TableColumn<ObservableList<String>, String> column = new TableColumn<>(
                    columnNames.get(i)
            );
            column.setCellValueFactory(param ->
                    new ReadOnlyObjectWrapper<>(param.getValue().get(finalIdx))
            );
            tableView.getColumns().add(column);
        }

        // add data
        for (int i = 0; i < N_ROWS; i++) {
            tableView.getItems().add(
                    FXCollections.observableArrayList(
                            dataGenerator.getNext(N_COLS)
                    )
            );
        }

        tableView.setPrefHeight(200);

        Scene scene = new Scene(tableView);
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

    private static class TestDataGenerator {
        private static final String[] LOREM = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc tempus cursus diam ac blandit. Ut ultrices lacus et mattis laoreet. Morbi vehicula tincidunt eros lobortis varius. Nam quis tortor commodo, vehicula ante vitae, sagittis enim. Vivamus mollis placerat leo non pellentesque. Nam blandit, odio quis facilisis posuere, mauris elit tincidunt ante, ut eleifend augue neque dictum diam. Curabitur sed lacus eget dolor laoreet cursus ut cursus elit. Phasellus quis interdum lorem, eget efficitur enim. Curabitur commodo, est ut scelerisque aliquet, urna velit tincidunt massa, tristique varius mi neque et velit. In condimentum quis nisi et ultricies. Nunc posuere felis a velit dictum suscipit ac non nisl. Pellentesque eleifend, purus vel consequat facilisis, sapien lacus rutrum eros, quis finibus lacus magna eget est. Nullam eros nisl, sodales et luctus at, lobortis at sem.".split(" ");

        private int curWord = 0;

        List<String> getNext(int nWords) {
            List<String> words = new ArrayList<>();

            for (int i = 0; i < nWords; i++) {
                if (curWord == Integer.MAX_VALUE) {
                    curWord = 0;
                }

                words.add(LOREM[curWord % LOREM.length]);
                curWord++;
            }

            return words;
        }
    }
}

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import javafx.application.Application;
import javafx.beans.property.ReadOnlyObjectWrapper;
import javafx.collections.*;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.stage.Stage;

import java.util.*;

public class TableViewCSV extends Application {    
    
    TableView<ObservableList<String>> tableView = new TableView<>();
    
    String headers[] = null;
    String data[] = null;
    
    List<String> columnNames = new ArrayList();
    // List<ObservableList> datas = new ArrayList();
    
    public void start(Stage stage) throws Exception {
        
        File f = new File("sample.csv");
        if (f.exists() && !f.isDirectory()) {
            FileReader fin = new FileReader(f);
            BufferedReader in = new BufferedReader(fin);
            String l;
            int i = 0;

            while ((l = in.readLine()) != null) {
               if(i == 0 ) {
                   headers = l.split(",");
                   for(int x=0; x < headers.length; x++) {
                      columnNames.add(headers[x]);
                   }
                
               }else {
                   data = l.split(",");
                   ObservableList<String> ol = FXCollections.observableArrayList();
                   for(int x=0; x < headers.length; x++) {
                      ol.add( data[x]);                      
                   }
                   tableView.getItems().add( ol );
                   // datas.add( ol );
               }
               i++; 
            }
        }
        
         
        for (int i = 0; i < columnNames.size(); i++) {
            final int finalIdx = i;
            TableColumn<ObservableList<String>, String> column = new TableColumn<>(
                    columnNames.get(i)
            );
            column.setCellValueFactory(param ->
                    new ReadOnlyObjectWrapper<>(param.getValue().get(finalIdx))
            );
            tableView.getColumns().add(column);
        }
 
        tableView.setPrefHeight(200);

        Scene scene = new Scene(tableView);
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

}