You can save the attachment in the following way:
New major steps start on new lines.
Open the message.
Tab, perhaps once, to a button that says something like button unchecked.  It doesn't identify its purpose, evidently because of an accessibility flaw.
When you are on the button, press the space bar.
You can now move in a list but your program may be set to display the attachments not as a list but you may have to move from left to right instead of up and down.  If you move up and down and there are multiple attachments, you may move to some but not all.
Try moving both ways to see how your computer displays multiple attachments.  You will know if you are missing any or not landing on them all if you move in the wrong way by comparing both directions.
When you are on an attachment you want to save, open the context menu, down arrow to save as and press enter.
The save as dialog will open.  You can tab around to see where the attachment will be saved, then tab back to where you usually work and save the attachment.
The field that shows where the file will be saved will say address in Windows 10 and you will hear other speech such as tool bar but after the word address you will hear a folder, such as downloads.

After you save that one, move to another one and save it.
When finished, press escape perhaps twice, once to close the list, again to close the message.  I didn't pay attention to just what happens but that is my guess.  Pressing escape, however many times is necessary, will close the attachment list and the message.

I said you can tab around to see where the attachment will be saved.  Once you know where one will be saved, all future ones will be saved in the same place unless you change the location so checking once is all that is necessary.
Gene