I dont think it is possible, but you can create a separate sheet and add it at the end of the earlier sheet in dashboard. so it looks the same way as it is in image.
In the current way you have this data structured i don't think that this is possible (if using the Grand Total functionality).
However, i would recommend adding this information in a second column to show Running total with a secondary calculation of % of total:
Add table calculation > Calculation type: Running Total > Perform a secondary calculation on the result > Secondary type: Percent of total
The other option, as Venkat mentioned above would be to simply create two sheets and place the % sheet below the other.
Hi @Venkat @CharlieArcher,
Thanks for reply. I will try and let you know. Thank you very much.