Default Very light and fast rom?

Hi guys,
I have galaxy tab from couple of years and it's great device. I really love, specifically when I'm traveling.

Few months ago, I updated it to CM with ICS, but the performance is very low.

I'm using the tablet mostly for Internet and I want to be faster.

Is there any quick and light rom that I can install?
Or just the device is old according to the current standards?

Thanks for the replies!