My dining table can just and just fit on our dining table (it is a circular table that extends to an oval shape, so the corners go off the edge). There’s some space for the units boxes at the top and bottom of the board, but whoever is the Allies have to stack their boxes.
And whilst the battle board can fit on certain areas of the board like the south Atlantic or Indian Ocean, we use a separate table to conduct battles, which is fun as it feels like we are focused primarily on the battle and not the war, if that makes any sense? Sure it takes time to move everything over, but its a good time to double check unit numbers beforehand for dice roles.
I sadly don’t have a good system for chips and other universal pieces, but next game I will be trialling using a re-purposed tin that can just be passed around between people, or even left in inactive areas of the board.
I don’t know exactly how much space you have or if this is useful to your situation, but its what I do to make use of the little space I have on the table after the board goes on. Don’t forget about where to put all your spare pieces as they need space too!
p.s. I also have a crazy creative idea in my head for a custom portable-cum-interlocking wooden table-top that could support itself on a slightly smaller (but not tiny) table. like SiredBlood’s on YouTube but way more complex (and difficult to make)