I don't know if this is how you'd do it in markdown. My text tables are generally done this way:

    +-----------+-----------+-----------+
    | label a   | label b   | label c   |
    +-----------+-----------+-----------+
    | r1f1      | r1f2      | r1f3      |
    +-----------+-----------+-----------+
    | r2f1      | r2f2      | r2f3      |
    +-----------+-----------+-----------+