Posted by mojavelinux on Mar 14, 2017; 10:35pm URL: https://discuss.asciidoctor.org/Table-include-macro-tab-delimited-files-tp5374p5379.html
I think a ticket for an include macro option to preserve tabs is also
needed.
The include directive does not remove tabs by default. Only if you set the indent attribute on the include directive and set the tabsize document attribute will tabs be expanded, but that's intended for use with source code, not tsv.