The keyboard shortcut for vertical block selection:
To select code block vertically in your visual studio code, use Shift + Alt and then use the mouse to select lines vertically, from top-left to bottom-right.
Shift + Alt + Select with mouse
Vertical code block selection example

Note:
This keyboard shortcut for vscode vertical select is tested on Windows 10 and Windows 11 Visual Studio Code Editors.
You may find other interesting and time-saving keyboard shortcuts in the vscode listed below: