How to fix next book tablet from freezing up and delay on touch

First try just restarting the tablet (turn it off, then back on). This alone may resolve the issue. I would also suggest thoroughly cleaning the screen. Also, if you use a screen protector, I would try removing it/replacing it.

Should those not resolve it, they you may want to go into "Settings" and update the touch screen info. Most tablets have it where you can calibrate the sensitivity in there. You might also want to try a calibration app.