To compare: The Dutch TT Association (NTTB) has around 35.000 members, in a country with 16.7 million inhabitants.
Read on the site of the NTTB: "At this moment we are a relatively small sports association..." xD
Just to compare also : the Belgian (divided into Flemish part and Walloon part and Brussels part ; yes Belgium is a very complicated small country) table tennis associations have about 25000 members (i would say 95% of them actively playing in competition, some are just on the list for practical reasons) in a country of 10,8 million inhabitants.
I just spoke to a 2nd division player of Belgium , and he said the Belgian youngsters will not do good in the future, the associations in Belgium are divided, not enough good coaches (one of them just stopped because of health problems, a small country with the typical Belgian fighting between Flemish and Walloon parts making the functioning of table tennis organisations even weaker).
He also said that the Italian open junior event is not a strong one, so the Belgians winning the doubles final doesn't mean too much really.
On world level there is only China, Japan, Korea, Germany, France who will deliver the future players (and here and there an individual talent of course).