The design is a row-column design. It is actually a generalized latin square design that is also carryover balanced.
A matrix with 10 rows corresponding to the first 10 assessors in a fictional uniformity trial, 5 columns corresponding to the five periods.
There are five products to be tested, numbered 1,...,5.
Kunert, J. (1998): Sensory experiments as crossover studies. Food Quality and Preference 9, 243-253 (design f2).