class with a lot of methods

I have a class with a lot of functions in it:

MyClass.cs Methods:

• Login

• Upload file

• Upload Folder

• Upload large file

• Download

and many more.

the problem is that the class grows and grows, and it's start to be not comfurtuble to write the whole methods in same class.

In one hand I want to invoke the functions like:

var myclass=new MyClass();
myclass.SomeMethod();

but the price is to put all classes in same file.

I there any design pattern for this? or any other ideas would be appritiated