A butsudan is a shrine memorializing dead relatives in homes of Japanese Buddhists. Although I am not Buddhist, this butsudan set up that I received from my Buddhist grandma is hands-down one of the best things someone has given me. It gives me a place to say hello to my dad every morning and vent if something is going wrong in my life.
Besides being a place to communicate with deceased family members, the butsudan is a place where you can make offerings (kumotsu) like food to them. I admit I don't offer food to my dad on a regular basis, but I do offer food on special occasions or if the food has special meaning to me.
Common offerings include seasonal fruit and rice. Pictured here is a Fuji apple from my sister's garden and a little bowl of rice. Japanese people NEED rice, even in the afterlife.
Contrary to my simple kumotsu here-- my grandma is much more experimental and contemporary with her offerings. I have seen her offer pretty much everything, from potato chips to cigarettes.
I asked her what she does with the food "I eat it!" she says. I was very relieved to hear this since I really hate throwing food away.