The alledged etymology
of the word "fika" is one of the strangest I have heard so far:
There is a Swedish "secret language" called fikonspråk (English: "Fig Language"), somewhat similar to pig latin. To say a word in this language, you split it after the first vowel, then say "fi" + the second part + the first part + "kon".
E.g. The Swedish word for coffee is "kaffe". Split after the first vowel and you get "ka" and "ffe". Adding "fi" and "kon" you get "fiffe kakon", which is "kaffe" in this language.
When fig language was at its most popular in Sweden, teenagers used it to keep secrets from their parents and other adults. Some "fig-words" related to the activities the teenagers wanted to keep secret, smoking and drinking coffee for instance, survived the language and is now part of "mainstream" Swedish slang.
So what has all this to do with "fika"?
Some people claim that "fiffe kakon", the word for "kaffe" i used in the example, was used for some time to mean a coffee break, but was later abbreviated to "fika".