Wikipedia has a list, which lists terror attacks based on ideology. Most of the non-Islamic attacks are older, the more recent ones tend to be related to Islamic extremists.
I think small sample size is irrelevant. If you check out terror attacks in Finland, Sweden and Germany, they don't seem to have as many as France or Britain, despite pretty high numbers of refugees and immigrants from Muslim countries. I think we're not a such a large political target as France, Britain or the States and that is partly why we've been relatively immune. But it seems that as ISIS continues to lose ground in Syria, there may be more terror attacks in Western countries.
This is an interesting article analyzing both the expectations of terror attacks since 9/11, vs. the reality. In many ways, the fear of terror attacks has not been borne out by the reality.
I agree that most people think that, but that doesn't make it automatically true. Since the religion of any other terrorist (or even mass murderer) is not generally part of the story and motives can be hard to define, it's impossible to know if other "religions" have more or less killers in their midst than Muslims. People who attack and kill abortion providers, for example, are not generally thought of as 'Christian terrorists' - yet what else are they? White Supremacists are heavily influenced by "Christian" ideology, yet nobody would call them "Christian terrorists" when they set fire to buildings or attack people.