Regading the meaning of "X,Y = load_coffee_data(); "

Can someone help me understanding the meaning of this given line

It means there is a predefined function with the name load_coffee_data, and if you call it, it will return two variables - X and Y.

so we are assigning x and y to load coffe data?

load_coffee_data returns two things, and the two things are assigned to X and Y respectively.
For example, in the following code, X contains 'hello', and Y contains 'world'.

def dummy():
  return ('hello', 'world')

X, Y = dummy()