How to: Add, Move, or Delete a Matrix (Report Designer)
In Layout view, in the Toolbox, click Matrix.
On the design surface, drag a box to the size you want the matrix to be. Alternatively, click the design surface to create a matrix of fixed size.
Drag a field from the Datasets window onto a matrix cell.
Note: If the Datasets window does not appear, in the View menu, click Datasets.
If you drag the field into a cell in a table column that does not have a header, the name of the field automatically appears in the column header.