Is it possible to create a data source from SharePoint 2010 list using Microsoft flow?
As a short answer: Yes, It's possible.
Microsoft Flow is a public cloud service only. However, you can securely connect to your own on-premises services through the
on-premises data gateway.
The supported data sources are:
- SQL Server
To configure on-premises data gateway for SharePoint check Understand on-premises data gateways for Microsoft Flow