I'm not that sure what they wanted to say with "slab of concrete" either I understand why they used the word "entertaining" any direction to undrestand these two will be appreicated

At 1:32 slab of concrete for entertaining. The tenant can put a grill out there, table and chairs


His "slab of concrete" is normally called a patio. He says "patio set" as he goes down the stairs right after that, which would be something like a wrought-iron table and chairs.

We say "entertaining" when we mean "having guests over for a good time".