When I create a class or a function file in octave. Is there a possibility to give the file a name that is different from the classes/functions name? (Class test is in the file test.m, but i would prefer to name the file for example test.class.m)
# test.m
classdef test
% ...
endclassdef
No. The way Octave is designed, classes and functions must be defined in files whose file names exactly match the class or function name. This is so that, given a function or class name, Octave knows where to locate its definition on disk, so it can lazily load in their definitions as they are needed by other source code, instead of having to load the entire source tree up front.
The exception is "command-line" functions, where you can define global functions inside a script, and their definition appears when the script is executed. This isn't a good way to organize code for larger projects, though, because you'd need to arrange for execution of all the scripts at the appropriate time, before those function definitions are needed.
If you want to distinguish classes from functions, you have the option of sticking them in subdirectories named @<class>, for example, @test/test.m.