
That is usually caused when you brush a thumb or palm across the mousepad on the laptop, thus moving the cursor. You should be able to adjust the pad sensitivity in Control Panel
It can still be your touch pad. It is really hard to notice when you touch it.
Pretty easy way to test it is to put a post-it sticker on the touch pad. If the cursor stops jumping, there is your problem. If not, you may have something nasty on your computer and you should scan it for viruses/malwares.