In the name of Allah

I easily use this method

For example you are in a worksheet and have written 3 functions fog(f,g), rez(x), intvec(v) and 2 global variables a,b assigned to some values.

After your definitions finish, you can easily use this command

save fog,rez,intvec,a,b,"lib1.m"

All the works are finished. You want to load this library in another worksheet; simply use:

raed "lib1.m"

And enjoy your functions and global variables.

In the name of Allah

If your Vector is v then:
M:= Matrix(m,n,(i,j)->v[(i-1)*n+j)]);

Best wishes and prayers

If you see the task manager performance tab it seems to be parallelized at the first glance. But it may, is the result of the OS parallelizing which divides the work of one core of CPU on all of them.