Anyone else's 9-10month old just crying when mama isn't sitting right next to them?

Krys

We have toys scattered all over the house. However my son cannot sit alone with his toys. I have my work desk 3 feet away from him, but when I try to sit and get some work done he starts screaming non- stop until i sit on the floor with him. is this just a stage until he can feel more independent? should I encourage him to play alone ( I'm always within view)