If you try to create a Dynamic Share on the User Role table (sys_user_has_role) you will see this error message:
“The table selected is not currently supported. Please choose a different table.”
You can Bulk Share the User Role table. We recommend using Scheduled Bulk Shares.
For more information on Scheduled Bulk Shares visit: https://docs.perspectium.com/display/fluorineplus/Create+a+scheduled+bulk+share