Strange knife

[Sajen]

Just have a look inside "Traditional Weapons Of The Indonesian Archipelago" from Albert G. van Zonneveld, page 34. This choppers are described here as Bendo and it is written: "A machete in the shape of an axe, mainly used for harvesting the aren palm." And further more: "The short, broad and heavy blade serves this purpose excellently."
Hope this answer your question.

Regards,
Detlef

Add information: https://en.wikipedia.org/wiki/Arenga_pinnata