I think a small and well-chosen selection of games would be a great idea.
The folks here have the right idea about the types of games you should be getting. I used to work in a toy store, and people always wanted to buy games for kids but had no idea what to get. If people value you for book recommendations, they will value you for game recommendations. Also, there’s a lack of good games for kids that are too old for little-kid games but can’t read well enough for most games for older kids, so if you can get some in that category, I’ll bet they’d sell. (I Spy games are good for this)
And your adult patrons will certainly appreciate having better strategy games available.
Settlers of Catan and several varieties of Fluxx are great ideas. You could even get some “plants” to start up a game of Fluxx and invite other patrons to be dealt in. It’s such a silly and fun game that once people try it, they will likely buy it.
Quiddler is a must. It’s a card game that’s like a cross between scrabble and gin rummy, and I think it’s a heck of a lot more fun than scrabble. It’s usually sold side-by-side with Set, and that’s supposed to be good as well.
I just tried Chrononauts last night, and that was a hoot.
Fluxx, Quiddler, Set, and Chrononauts are all just decks of cards, too, so they won’t take up much space in your small store.
For little kids, you should definitely get What’s Gnu. It’s fun for adults and kids to play together, and hits that hard-to-buy-for age group.
As far as coffee mugs–please get larger-sized ones. Having some from a local potter on consignment might be a nice way to get some unique merchandise at low risk to you.
Since people are already buying books with accessories, why not take a few and pre-wrap them together as gifts. Like take Walter the book and Walter the plush and put them in a cellophane gift wrap with a fancy curly ribbon. Knock maybe a buck off the price of the two of them together. If they don’t sell, just unwrap them and sell as normal. Very low risk.
And a suggestion that may help sell more books–make up a few lists targeted toward gift buyers. Not everyone will ask for help. Like you can do “10 Great Children’s Books You May Not Have Heard Of” or something. Laminate it and velcro it to the edge of a shelf in the children’s section.
How’s your selection of crossword puzzle and similar books?