Matrix.Zero(n) returns a zero matrix of size $n\times n$.
If the option “Userdata” is set to false (default is true) the output is returned as a table of table rather than a pointer (compare Matrix.ToUserdata() and Matrix.ToTable()).
print(Matrix.Zero(3))
{ { 0 , 0 , 0 } , { 0 , 0 , 0 } , { 0 , 0 , 0 } }