Hi Collin,

I presume from your question, given the saw size of 10", and your mention of a fence and table, you are referring to either a portable job-site tablesaw, or a chop saw of some kind, and not a portable circular saw, since none of the Japanese manufacturers make a 10" circular saw. There is a 9" one available in Europe mind you.
Japanese jobsite table saws are designed for portability and light weight as primary concerns, and are intended for trim carpentry, flooring work, etc., not ripping 4x stock. Mafell and Bosch make similar products.

If you are referring to a miter saw of some sort, I don't know what you mean in regards to wimpy tables, though I do have my issues with both Hitachi and Makita sliding compound saw fences. The Hitachi ones shift position if the slightest kickback occurs while cutting, and the Makita ones can come out of the factory warped.
Anyway, until I know exactly which machine you are talking about, I will put off giving a more considered answer.
As to the design idea of Japanese tools, they are often slimmer and lighter than the western equivalents. Just like with Japaense cars vs American cars. I would say what comes with the Japanese design in tools is finesse and accuracy. With Hand tool cutting edges in particular the Japanese lead the world without question. The ideology is different. Western cutting tools get names like 'panther', shark' 'boss', 'dominator', 'Fat Max' etc - all images of power and, often, a savage ripping up of material. Japanese tools tend to get more poetic names, like "Jewelled Dragon", "Pure Spirit", "Evening Calm on Awaji Island" etc. A totally different mindset.
As far as heavy duty tools, well, there are a lot of Makita and Hitachi (and Ryobi) products that just don't come to this side of the Pacific. All three companies make massive, heavy cast iron jointers planers and table saws, not to mention machines you may have never seen before, like super surfacing planers. My 400 mm Hitachi resaw bandsaw, for example, has a 4"+ wide blade and weighs 1400 lbs. I would not categorize it as wimpy in any respect whatsoever. Japanese impact drivers, while being light and compact, can take tremendous abuse year after year and are very reliable tools in my experience. Ditto for the hollow chisel mortisers, chain mortisers, portable planers and other timber frame specific pieces of equipment they make. Ryobi stuff available in N. America is all the low end crap of their range - but they make automated tenon cutting machery, large portable planers and other heavy duty tools that we never see over here. It's too bad, becasue if people saw the good stuff, they would form a different opinion of the company's products I think. And even their low end stuff is better than a lot of products out there.
As for European power tools, I have used Mafell, Festool, Elu, Metabo, and Bosch. All are good - in particular I have switched pretty heavily over to Festool in the past two years, now owning a few of their routers, the jigsaw, driver drill, dust extractor, etc. Excellent stuff. Mafell stuff I am a bit mixed about. It seems well made, but a little crude. Planer bases, for example, are not finely ground, and for the money, in most cases, I just don't get it. A Mafell 12" beam planer is double the cost of the Makita 12", but no better in any way as far as I can tell. In fact, I prefer the performance of the Makita - the adjustments for front shoe depth are more refined, the base is smoother, and it's quieter.
The Mafell drilling machine is sweet, as is their protable bandsaw. And if I were looking for humongous 2-man circular saw, that would be the company to turn to. Their smaller circular saws however seem a bit of a rip for price. They have an similar guide rail system to Festool, and I can't imagine the quality being any better than Festool, yet you pay 3-4 times more money for Mafell. What gives?
It seems to me that the best stationary and portable power tools are made by Germany and Japan. Both countires have cultures that emphasize quality and precision in their manufacturing and products. Their populations demand that level of quality. Over here, for the most part, low price is king and that is a main reason everything comes, it seems, from China. The Chinese and Taiwanese are capable of making equipment on a par with the Japanese and Germans, but we wouldn't buy it, sad to say, even if they did. So they sell us the low end crap.
The German companies Martin and Altendorf make sliding tablesaws without equal. The nicest single surface planer I have ever seen is a Makita - it's probably $40,000 or so mind you. The Martin shaper is the best, without question. The Hoffmann jointer is superb. Shinx, another Japanese company that you don't see in North America makes awesome 2-sided and 4-sided planers, and probably the best super-surfacers. When I say 'best', I should qualify that statement to: 'highest quality and performance, money no object'.
I hope my ramblings above answered your question to a satisfactory extent.

Chris