With the Repeat Matrix On setting, you organize the data according to a specific key information. The matrix is then displayed several times, with the respective value of the key information as a table header for each table. The single matrices then contain only the data referring to the respective item.
For example, if you use a matrix showing sample information, you can repeat the matrix on the sample type. As a result, there will be one matrix for each sample type in the sequence. The sample type is the matrix header, and each matrix contains only the information referring to the respective sample type.