add rows after total

PowerBI doesn't really let you do what you want.  You could hack it but would not be dynamic and it will require you to write a measure to calculate the amount for each category

Transactions Measure = CALCULATE([Amount],table[Category]="Transactions"

etc...

You coudl then put them in a Matrix Visual with the formatting set to display columsn on rows and add each of your individual measures into the values of the Matrix along wiht yours savings. 

What I usually do is put a Card, Guage or other simple visual off the side with the other measure.

There are some other hacks in PowerPivot for Excel that woudl allow you do what your trying to do without writing all the extra measures but they won't work in PowerBI.   I saw an announcment that there is a pending release of PowerBI that will have paginated report capabilties and this might have the functionality your after but I dont' think there will be many details about it befor the upcomming BI Summit next week in Seattle.

https://powerbi.microsoft.com/en-us/blog/power-bi-expands-self-service-prep-for-big-data-unifies-modern-and-enterprise-bi/