Sorry, I don’t know what is this element called in English. It is an electric power cord with multiple sockets to allow multiple appliances to be plugged into it. In Spanish it is said to be informally a “zapatilla”, but in English?
This varies country to country, even internally within English speaking countries.
In the UK, in shops they usually refer to it as a “multi-way extension lead”. Also referred to as a “socket strip”, “socketboard”, “power strip”, “extension socket”, “extension cable”, “plug board”.
Probably a few other things.