Among the huge customization options it has, you can control the text size in form of zoom. To do change it, just use the following keyboard combinations:
- (Ctrl + = ) For Zoom in.
- (Ctrl + - ) For Zoom out.
- (Ctrl + 0) For Zoom reset.
Also, as with everything on this tool, you can access this functionality from command palette (Ctrl + Shift + P), and type "zoom" (you can fine-control the editor zoom from here):
If you haven't tried it yet, you can download Azure Data Studio here.