If you connect up EIGHT appliances to your 8-point power board, its up to YOU to calculate and control the load so you don't overload the circuit breaker devices (either on your 8-point power board or the main house switchboard).
They are making you want to buy the bigger power board just for the idea or hope of more power
You can think of the power socket in a room as already part of a power board. If a room has 3 sockets the power for those 3 sockets is coming from one feed line (one board) so if you overload the sockets you risk an electrical short. Imagine a power board of 8 sockets and you plug power boards into each of those 8 sockets... see what I'm getting at? A power board is designed to split the power from a socket into 2 or more feeds and a large board (6 sockets or more) will usually have its own internal breaker for safety. If you overload a power board the boards breaker kicks in not the main lines breaker.