This tool is a copy of the Swiss Halmenschaber. that is used to split and smooth straw. By inserting the  point of the tool  into the hollow stem of a straw you can split the straw along its length. The flat edge of the blade is then used to smooth the straw.
 
Construction: Wooden Handle, Blunt Steel Blade
Approx: Handle 8 – 9cm Blade 2.5 X 4 cm