No... You are not allow to take them... As they are part of the airlines proporty... And if you take them without asking, you could be charge for thiefing...
However, if you hide them well... The crew will simply not realise that you have taken them... So yes... There are people who take these things... But when they are not being seen...
On the other hand, there are airlines who would give these to passenger for free... But usually to their First Class passenger if they even wish to take them...
But surely, if the crew know you are an aviation fans... They will usually let you take them for collection... But not for sale...
At the end, for their spoons and other stuff on the meal tray... Usually the crew would not mind when they see bits missing... However, I am not suggesting you to take all the stuff... As this would be unacceptable...
Last time when I flow with Virgin Atlantic... I have talked to the crew for a bit... And they notice that I was a aviation fans... So they ask me if I would like some of these Virgin wine glasses... And I was given a couple for each member in my family...
Having said that, although I have had some of these good experience which crew just give you them... Do not think that they have to let you take them as they are the airlines proporty... However, the crew will usually not mind as long as you ask and its for your own collection only...
其實一律係犯法的. 只不過係航空公司, 隻眼開隻眼閉. 但依家大部份餐具已轉為膠叉腸匙 ka la 喎. 都唔會攞啦. 如果係鐵個 D, 一般都可以攞既. 呢 D 係不成文規定嘛. 有時 D 玻璃水杯好得意, 又印左航空公司名; 都會攞的. 但毛毯就唔好 la 掛. 咁大張.... 出海關比人查行李實死.