Can the iPhone charging block be installed in a power strip?

You can plug the charging block into any compatible receptacle whether on a wall, extension cord, power strip, etc.

Maybe I'm not understanding your question and if that is the case I'm sorry.

Why do you ask?

The Anker 727 Charging Station power strip does quite well at reducing the numbers of chargers needed: 2 USB-C ports, 2 USB-A ports, and 2 AC sockets (for other uses or added chargers). There are similar products from other vendors, and variously with different combinations of connectors.