This appears to be a convertible tablet/laptop with removable keyboard.
I like to use a USB Keyboard on these to eliminate potential detection issues with the dock keyboard.
In any event, I don't think you are getting to the boot menu. Here is some information I found for Sony's in general.
But you should be able to stop at a menu and choose the boot device.
What is the key for boot menu in Sony VAIO?
The Sony VAIO boot menu key may vary depending on different models. But you can try the Assist button, F11, Esc, and F10 keys. If these keys don't work, you can also try F1, F2, and F3.
How do I boot from USB on Sony VAIO?
Connect a bootable USB drive to the Sony VAIO laptop.Power off the PC and then press the Assist button to enter the boot menu window. Or restart the PC and then press the boot menu key like F11, Esc, or F10 to open the boot menu window.Choose Start from media (USB device/optical disc) option.
And Rufus latest version has the ability to download many installation .iso files.
Make sure you are creating an EFI/UEFI boot stick. The documentation indicates it came with Windows 8, so almost assuredly EFI Secure boot as opposed to MBR.