He with either have 38 tables with 4 people at each table, or 19 tables with 8 at each table.
by putting two chairs
5
7 people will fit
If the rectangular table is 60inch x 24inch the recommended seating if for 2 people. You can find seating recommendations here: http://www.banquettables.com/tables/tableandchairsetuparticle.cfm
120cm (4') Round Table - Seats 6/7
6
5
six
5
An eight foot table can seat up to ten people but should be sat for eight if possible. Four on each side and if you have to, one on each end.
The chairs are 11 1/2" high at the seat and the table is 21" high.