Usually the people who stay more than one or two nights in someone else’s home are very close friends or relatives of the host family. They know each other well and are most likely to make such a visit during a vacation or holiday.
When you become a “houseguest” for several days or several weeks, you feel pressure to adapt to the rhythms of the household and to make as little trouble for the hosts as possible. You want to indicate with a gift at the beginning of your stay how much you appreciate being asked to stay in the guest room and share meals.
A houseguest might bring as gifts a set of guest towels, place mats with matching napkins, several bottle of good wine, a set of cocktail glasses, or a nice potted plant that does not require constant attention. In other words, the gift is to be used and/ or enjoyed by all the members of the family. It is not necessary to take an expensive gift, because you will be able to reciprocate some day in the future by having your hosts stay in your own home.
You can offer a “gift” during your stay by either inviting the family out to dinner or even by offering to cook a meal at home.