I am currently doing tabletop game design, prototyping and so on.  For me, having the ability to read documents approximately along the lines of what I get with actual documents is helpful.  This is why I am looking at a tablet.  Something roughly the size of a book would benefit.  I am currently moving in an area where my shot of doing anything professional involves designing tabletop games.   

As far as a phone goes, I am so strapped for cash, I can't afford a smart phone's data plan.  I have a phone with limited minutes used to call when in need.  I am also happy with using Wifi to access the Internet, so I can avoid paying for a data plan.

Games mate, it's all about games.

But, according to what you say, I'd suggest get a tablet, then get a 3DS/PSV.

Well I live in the UK and a decent android tablet will run you something around £300 (even more if you are looking at an Ipad). Most dual core smartphone plans are about £400 overall now (my Galaxy S2 plan was about £500 for 24 months at the phone's launch). So I don't know, I think smartphones have come down in price quite a lot so it might be worth researching something that may fit your work purpose. It seems like you could really benefit from the Galaxy note as its quite big.

But if you are really strapped for cash, then you could try to go for one of the cheaper end tablets, they won't have as many functionalities but will definitely serve you with all that you mentioned. From what I can understand of your situation you probably shouldn't even be considering a handheld gaming device now, they won't help at all with your job.

If you want games, go for the 3DS. If you want practicality, go with a Tablet.

If you require portability with high end specs and a disc drive: laptop.

If you require portability, need it for work purposes but don't need disc drive/high specs [ie you are not a designer]: netbook.

If you don't need it for work, but for browsing on the go and such: smartphone.

Personally the only viable use I see for tablets is for use at home, basically as a big smartphone. I would keep one in my living room to use for light browsing instead of traveling upstairs to a full desktop every time I need the internet. If I can't carry it in my pocket then it doesn't have 'casual portability'... sure it's possible to carry a tablet in a bag, but the same can be said for a laptop, whereas a smartphone does the same stuff as a tablet and is smaller.

For gaming... it depends entirely on your tastes. I am not fussy about having epic or deep experiences for gaming on the move. If I had a 3DS or Vita it would be used in places like on the train, but in those situations I would be perfectly happy with little flash game-like experiences.
The reason to buy a 3DS or Vita is if you want to play the games that are on them... simple as that.

To say more on what I recently posted:

I would actually recommend you get a Tablet. I would think you would of had at least one Console (as you are a VGChartian) and in this case a Tablet would extremely help you out! Wait for the 3DS, don't get it now.

I am wandering about the optimal solution too.

Today I have nothing, but i believe I will get a smartphone to be able to go on the internet (from what Ive seen smartphones are decent to surf the web with) and then I'll get a 3DS for gaming when I'm on the road.

What sux though is that smartphones are so expensive. A good one with a big screen costs like $500 or more.

Tablets disgust me. They're too big to be smartphones. They don't have physical interfaces like laptops/notebooks. They don't have buttons like portable consoles. I will never buy a tablet.

I have a smartphone that I take everywhere (Droid 2 but I'm upgrading it to a Droid 4 in the near future) and a little case that houses my PSV and 3DS. Sometimes I just take one or the other, though.

which is better? A computer or a toolkit?

I'm a kind of guy who likes to build all sorts of stuff. I like the options of a computer, but it's not really going to help me build a desk. Sure I could use it for internet to look up building advice, but I can use my phone for that. My question is, what should I buy to build a table.

Lol! XD They are too alien to you D21?