Lua: Function Table

I am trying to store different functions in a table, but for some reason this will not work as I thought. Here is my "code"

fn_table = { aFun1=print, aFun2=self:getSpeedLevel, aFun3=.... }

Now the problem is that I can do this with built-in functions such as print, assertand so on, but it will not work with other functions that I have.

I get an error: "... function arguments expected around '}'

Is it possible to save this function?