Sure. You can create as many as you like.

Code Example

1. import controlP5.*;
2. ControlP5 cp5;
3.  
4. void setup() {
5.   size(700, 400);
6.   cp5 = new ControlP5(this);
7.   for (int i=0; i<100; i++) {
8.     createListBox(i);
9.   }
10. }
11.  
12. void draw() {
13.   background(0);
14. }
15.  
16. void createListBox(int num) {
17.   ListBox l = cp5.addListBox("myList-" + num).setPosition(random(width), random(height)).setSize(100, 100);
18.   for (int i=0; i<5; i++) {
19.     ListBoxItem lbi = l.addItem("item " + i, i);
20.   }
21. }

Not sure what you have in mind. ControlP5 is a very suitable library to create all kinds of gui elements. If you want to display incoming stuff there are endless possibilities to visualise them using Processing as such.

ControlP5 is a gui library. I think it's a bad idea to stream incoming data into gui elements and try to save it. Use the library for gui stuff (buttons, sliders, etc.). But for incoming data, it's much easier to store and display it using regular processing code (see the Processing reference). Then it's also relatively easy to save it (see Topics > File IO > SaveFile1).