But for checking for e-mails, searching the Wikipedia while reading if I have some question and checking for Twitter mentions do I need a huge amount of data?
I plan to to this one hour or so every day.
Those are my goals. No music, no photos, no videos: for those I will use WiFi.
That should be fine depending on how much data you have in your plan. But you got to make sure you are not allowing your iPad to do anything else in the background via cellular. When you take your device out of the box, it is likely not restricting cellualr and it is using it like it were hooked up to WiFi.
I use wifi both at the house and office and leave it on at all times. Only when I am out in the field and where there is no WiFi do I turn on cellular for stuff I have to get done. Make sure you are restricting cellular from doing anything except what you want or it will use it for stuff that is not important. I turn cellular back off when not in use.