LWJGL Program continually using RAM

Hey guys so I just started working on a game with LWJGL and I have the display working fine and I drew an image on the screen for the main menu with Slick2d but, when I run the program I notice my ram usage starts at 1.6GB and it just keeps going up 1.7GB 1.8GB ect.. But when I close it my ram usage goes back down to 1.6. Does anyone know why this is happening?

Here is my source:
[spoiler]

Code:

// Main class

package LWJGL2DGame;

import org.lwjgl.LWJGLException;
import org.lwjgl.Sys;
import org.lwjgl.opengl.*;

public class Game {

public static final int WIDTH = 800;
public static final int HEIGHT = 600;
public static final String TITLE = "Rpg";
public boolean running = true;

private long lastFrame;

Render render;
MainMenu mainMenu;

public Game() {
try {
Display.setDisplayMode(new DisplayMode(WIDTH, HEIGHT));
Display.setTitle(TITLE);
Display.create();
} catch(LWJGLException e) {
System.out.println("ERROR IN CREATING DISPLATY!");
}

render = new Render();

// Initialization
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, WIDTH, HEIGHT, 0, -1, 1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glEnable(GL11.GL_TEXTURE_2D);

mainMenu = new MainMenu();

getDelta();

while(running && !Display.isCloseRequested()) {
render();

Display.sync(60);
Display.update();
}
Display.destroy();
}

public long getTime() {
return (Sys.getTime() * 1000) / Sys.getTimerResolution();
}

public int getDelta() {
long time = getTime();
int delta = (int) (time - lastFrame);
lastFrame = time;
return delta;
}

public void render() {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
GL11.glLoadIdentity();

mainMenu.loadMainMenu();
}

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

}

Code:

// Main menu class

package LWJGL2DGame;

import org.newdawn.slick.opengl.Texture;

public class MainMenu {

Render render = new Render();

Texture mainMenuBg;

public MainMenu() {
}

public void loadMainMenu() {
mainMenuBg = render.loadImage("MainMenu");

render.drawImage(0, 0, 1025, 615, mainMenuBg);
}
}

Code:

// Render class

package LWJGL2DGame;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import org.lwjgl.opengl.GL11;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;

public class Render {

public void drawImage(int x, int y, int width, int height, Texture tex) {
tex.bind();
GL11.glBegin(GL11.GL_QUADS);

GL11.glTexCoord2d(0, 0);
GL11.glVertex2i(x, y);

GL11.glTexCoord2d(1, 0);
GL11.glVertex2i(x + width, y);

GL11.glTexCoord2d(1, 1);
GL11.glVertex2i(x + width, y + height);

GL11.glTexCoord2d(0, 1);
GL11.glVertex2i(x, y + height);

GL11.glEnd();
}

public Texture loadImage(String path) {
try {
return TextureLoader.getTexture("PNG", new FileInputStream(new File("res/Gui/" + path + ".png")));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

[/spoiler]

Thanks in advance!