I tried to report a bug in https://www.magentocommerce.com/bug-tracking. In Version drop list, It only support CE 1.9.X.
The issue is
When I change Last Name in Edit Account Information, table quote is not updated.
When I create a new user, table customer_entity, customer_grid_flat and quote are updated with new user info.
Why the last 2 tabled are filled with user info?
Please go to following url https://github.com/magento/magento2/issues. Here you have to click on new issue button on left hand side on the top to create anew issue.
Before creating the issue search in the filters text box if same issue has been reported before. If not then create your issue and provide details like operating system, php version and Magento version.(Include full steps to reproduce the issue) .
If you can explain in detail "When I change Last Name in Edit Account Information, table quote is not updated." scenario, you may get some help.