The labelmatrix command allows you to lay out equation objects in an automatically sized matrix layout with labels for each row and column. Matrix brackets are automatically added to your result
The rlabelmatrix command places the row labels on the right hand side of the matrix.
labelmatrix(&A&B&C\\A&1&2&3\\B&4&5&6\\C&9&8&7)
rlabelmatrix(A&B&C\\1&2&3&A\\4&5&6&B\\9&8&7&C)
The labelmatrix commands are used in exactly the same way as the table command. Visit the table command page for more details.