So far as apples are concerned, they are in the genus Malus which includes both apples and crab apples, any fruit that is two inches in diameter or less, it is termed a crab apple. larger than two inches, it is an apple. So basically crab apples are miniature apples and many varieties are very tasty. Calloway, Harvest Gold, Dolgo are a few of the edible crab apples that lend themselves well to Bonsai.
Fig trees that produce basically very small pear like fruits aka figs are great for bonsai novices. Many varieties will bear fruit in the spring and again in early fall. Cherries will also work well as bonsai trees.
Coffee Trees make excellent bonsai trees, and even a good yard plant if you live in a warm enough zone. Not only does it have its aesthetic appeal, but it also produces 2 valuable crops. The coffee bean as well as the super fruit that encases the coffee bean. The red to purple fruits that encase coffee beans are referred to as a cherry, it is a stone fruit and the so called 'beans' are actually its pits.
Berries borne on trees such as mulberry, choke berries, kiwi berry, service berries, and many other berry producing trees will also work well as fruiting bonsai.
Kumquats grow in cooler regions where other Oranges and other citrus will not. See; Kumquats as Bonsai Trees
Other dwarf citrus such as Meyer lemon, Kieffer lime and Rangpur Lime also work well. Calamondin orange trees have very attractive blossoms and produce fruit in all seasons under the proper conditions. The fruit however takes a very long time to ripen and in my humble opinion doesn't really taste all that great.
Indoor Lemons Indoor Limes Indoor Fruit Trees
Indoor Mandarins Unusual Fruits and Berries Indoor Pomegranites