Why did Baltic families set places for the dead at festival meals?

In Baltic religion, the practice of setting a place for the dead at festival meals was rooted in the belief that the boundary between the worlds of the living and the dead was not real.1

Because the dead were considered to continue living invisibly and remained present at all important family occasions, the living felt a responsibility to provide for their welfare. Setting a place at the table—which no one else was permitted to occupy—was a central part of this extensive practice of feeding the ancestors. These meals were originally placed at the hearth, though in later developments, they were also offered in other locations such as the threshing house or the bathhouse.1