Start/Stop profile
You can click on the / button in the Actions column,
or to bulk start/stop profiles, you can select profiles and then click on the / button on the toolbar.

Browser size and position
If in the global settings you set Browser Position to Default,
The browser will appear in the upper left corner with the size equal to the screen resolution size set when you create profile
In case you set it to Grid. The browser's position, size and scale level will be set and arranged
accordingly on the screen.
Attention
Each profile can only run one session at a time, you will not be able to run a profile on multiple computers at the same time!