I know from personal experience just how slippy a tram line can be if you put a bicycle wheel on it. Very slippy indeed.
I try wherever possible never to cross them, but there are many cases where there is no alternative. If I do have to cross them then I know it is best to cross at right angles to the direction of travel. I will always try to get as close to that angle as possible. I will lift up my front wheel over the metal track, and unweight the back wheel by standing on the pedals as it crosses and moving my weight forwards. I put a great deal of thought in to it because I do not want to be measuring my length on the tarmac. Hitting the ground can cause serious injury. I don’t want to break or bend bits of my bike. But most of all it is the thought of some other road user going in to me, or over me, that concentrates the mind.
But you are not always given the optimum circumstances. A car, or a bus, or a pedestrian can mean you quickly have to alter your position and direction on the road.
So I was surprised to hear that more cyclists in Edinburgh are reporting falls involving tram tracks. Maybe it is wetter here, maybe there is greater awareness. But it seems to me to be extremely unlikely that we are as a group poorer cyclists or less careful cyclists than those in other cities.