He focuses on the Tomica line - well known for producing toy models of Japanese cars.
"Collecting toys is not a matter of how deep your pockets are; it's about whether you have the chance to come across toys that you fancy," he says.
Two years ago, Tam paid HK$30,000 for a made-in-Hong-Kong Tomica Mitsubishi Galant GTO toy car which he bought online.
It's the most impressive item among his 5,000-plus toy car collection. "It's impressive not because of the price tag, but the history behind it. What's special about this car is that it was made in Hong Kong. In the history of Tomica, there has only been one period, around 1971, that the brand outsourced production to factories in Hong Kong," he says. "Production in Hong Kong did not last long because of quality control issues, so only a very small number of cars were produced here. Although these cars are considered of an inferior standard, they're extremely rare."
Tam's collection dates back to his childhood.
"Many people ask me how much my collection is worth but I'm never able to provide an accurate number," he says.
"I have some really pricey cars that I paid thousands of dollars to get. I also bought some cars more than 20 years ago for less than HK$100, which would be worth thousands of dollars today, so I can't really tell the value of my collection in terms of money."
Taking care of such a huge toy car collection is no easy task. Once a week, Tam, who is in his 30s, needs to clean the dust from the cars. Hong Kong's humid weather adds to his concerns, as the damp can damage the cars, most of which are made out of metal.
"Many people use anti-humidity products to protect the cars. I discovered an easier and more economical way to preserve the cars - by using tissue paper. I wrap the cars with tissue and put them in the small paper boxes they come in," he says.
"I don't believe in waxing cars to make them look like they are new - the rust on the cars gives them a special appeal," he adds.
Tam says his toy car collection is actually good for his health, and helps him to relax. "I have different 'sets' on which I arrange the cars ... all my troubles go away when I play with my cars. I grew up with them; they're still my beloved toys."
Tam shares his passion for toy cars on his blog. "Many of the collectors that I talk to are from the mainland or Taiwan, and grew up travelling in Japanese cars, which led them to collect toy cars," he says.
This Easter, Tam will put exhibit part of his collection. You can check out his and other Tomica models at East Point City shopping mall in Hang Hau from now until April 21.