Plotting Board

[Bruce Parker (RIP)]

There is an artillery plotting board (like this Canadian one in the pic) but in surveying there is also a 'plane table' for plotting locations of features to create a topographical map, which might be what you have.

[rob love]

I recently picked up the tripod for these items if anyone wants to see it.

[cletrac (RIP)]

Maybe it's just called a map board. It's the right size to fit in the holding brackets behind the radio operator's seat in a 1A2 wireless body. Rob, lets see a picture of your tripod.

[cletrac (RIP)]

I came across a bunch of map-related stuff but don't know what would be relevant. It's shown here with the map board and tripod.
That little square black thing is a neat US morse code training device. There's also a proportional divider in the mail.

[cletrac (RIP)]

Here's a plane table from the manual of map reading 1939. They talk like these are the tolls you need when map reading etc. What's the thing that I didn't label?

[Chris Suslowicz]

A rubber for when you make a mistake?

[Bruce Parker (RIP)]

Originally Posted by Chris Suslowicz

A rubber for when you make a mistake?

Could be that. I bet it's level bubble for the table.

[maple_leaf_eh]

Originally Posted by cletrac

Here's a plane table from the manual of map reading 1939. They talk like these are the tools you need when map reading etc. What's the thing that I didn't label?

Less about map reading as topographic surveying. The surveyor draws everything he sees and plots it on the large paper sheet. It is rudimentary compared to modern survey equipment, but it is what they had and used for many decades.