Altar - Loki

Yes, if you're going to ask something of Loki than giving him an offering would be the way to go.

Actually I wonder how we are use the foods in altar. Just they should be stay or we should be burn them or like this something. (Actually I feel like we should burn them but I don't know) by the way I'm sorry for my english its not my first language.

Foods placed on an altar for Deities are often left for a few hours or overnight and then disposed of. You can dispose of them in several ways, burning them, throwing them in the trash or putting them outside for the creatures around you to eat (I would be careful with this depending on what creatures it might attract and don't leave the food close to the house). There is another method of disposing of the food, after offering it on the altar wait an hour or so and then eat it.