An official RaspberryPi 5 PSU is akin to a 27W mini brick which doesn't block any adjacent sockets on a power strip. However, the power bricks came with my N100 systems are similar size to 60-80W MacBook power bricks, they're way bigger, even if they're not significantly more powerful.
No, N100 systems do not contain their power supplies in the box. They're external.