Minimum 5 tables are required. For M:N (R1& R2) relationship count 2 tables, then for one side total participation, for such pair of entities we require 1 table for each relation (E1 R4 E4 & E2 R3 E3). Now, see we have 1:1 relationship between E4 and E3, we can add it in either E4’s or E3’s table. Now, the remaining R6 E5 can be merged to form another table. So, in total (E1R4E4),(E2R3E3R5),(R1),(R2),(R6E5) tables can be formed.