A summary table is a tabular representation of summary data, and is a useful data structure for statistical databases. primitive summary tables are basic building blocks of summary tables are basic building blocks of summary tables, and can be represented as relations with set valued attributes. in this paper we propose a set of summary table manipulation operators that together with an algebra of set-valued relations, form an algebraic language for manipulating set-valued relations and arbitrary summary tables we then describe a physical organization technique for summary tables, and discuss an implementation for summary table operators utilizing this technique.