Tab e slow

The more you have on the tablet the slower it will get. More and more apps, running apps all the time (not actually closing them), leaving the tablet on all the time, not clearing out caches and histories, leaving all your texts (if you have texts on that device) in the text messaging app, etc., will all slow down the device, a lot, over time.

Your best bet is to clear out the caches, histories, etc., clear out messages, actually close apps when not actively using them and restart (power off and back on) the device regularly and this should get it working faster again.

Additionally, you may want to make sure that apps you aren't yourself accessing the internet with, aren't accessing it on their own, which will also slow it down a lot.