Something like these colour-in play house if you have the room.
If you have a local library you could take out a range of books (mine allow me to borrow up to 12 per ticket)
A box of kapla planks (aldi and Lidl do similar sets for about £10). They look like nothing but keep my kids entertained for ages. It takes a lot of coordination, imagination and concentration.
A random box of lego (which you could get second hand and run through the dishwasher in a net laundry bag) is another really engaging toy.
A ream of plain white paper and some colouring pencils. Don’t buy the cheapest pencils as they break easily and pare away to nothing.
Football and skipping rope if there’s any option to get outdoors. (If you don’t have a garden, consider incorporating a walk into your plans) In my experience a good bit of time outdoors is the key to relaxed, well behaved children.
Junior monopoly is surprisingly good; easy enough for a 5 year old to manage with a bit of help, but not too dull for an adult.
Quiz questions. Make about half the questions child friendly because they will really challenge some of the adults. Think along the lines of...
In the fairytale Cinderella what animals did the fairy godmother turn into horses?
Who is Ash Ketchem’s Pokémon partner?
In Minecraft how do you make obsidian?
Just check with the parents to find out what their favorite shows, games and obsessions are and google quizzes on those subjects.
Name this dinosaur ...