What is MD?
A Markdown table is the one people actually write by hand: pipes between the cells, a row of dashes under the header. GitHub, docs sites and half the world's READMEs render them, and their one real subtlety is that a pipe inside a code span is text, not a column break.
What is TSV?
TSV is CSV with tabs, and the swap removes CSV's worst habit: prose is full of commas and almost never contains a tab, so fields rarely need quoting at all. It is what you want when the data is text-heavy and the quoting keeps going wrong.