Like the house, you have various slots to place the bed, table, decorations, etc. Some pieces of furniture affect gameplay. For example, sleeping in a specific bed reduces skill check difficulty by 2% for the next 24 hours.
Other items, like tables, wardrobes, a wine cask, and more, also offer functional benefits. You have to choose between aesthetics and utility at the beginning, but over time, you can purchase/unlock everything.