Is it possible to center tables in a markdown file?

Yes. You can have GFM tables in API Blueprint – check http://docs.tables.apiary.io for rendered version of the blueprint source bellow.

FORMAT: 1A

# Tables API 
Note: Tables can be handcrafted or generated at <http://www.tablesgenerator.com/markdown_tables>.

## Table 1
**Discussion option 1**

| Tables   |      Are      |  Cool |
|----------|:-------------:|------:|
| col 1 is |  left-aligned | $1600 |
| col 2 is |    centered   |   $12 |
| col 3 is | right-aligned |    $1 |

# Message [/pages]
## Create a Message [POST]

### Table 2
**Discussion option 2**

| Tables   |      Are      |  Cool |
|----------|:-------------:|------:|
| col 1 is |  left-aligned | $1600 |
| col 2 is |    centered   |   $12 |
| col 3 is | right-aligned |    $1 |

+ Request (application/json)

    ## Table 3
    **Discussion option 3**

    | Tables   |      Are      |  Cool |
    |----------|:-------------:|------:|
    | col 1 is |  left-aligned | $1600 |
    | col 2 is |    centered   |   $12 |
    | col 3 is | right-aligned |    $1 |

    + Headers

            Authorization:Bearer tokenString

    + Body

            { ... }

+ Response 201

If you use the standard documentation, use the <center> tag like so.

Blueprint

FORMAT: 1A
HOST: http://www.google.com

# Tables
Notes API is a *short texts saving* service similar to its physical paper presence on your table.

<center>

| Tables   |      Are      |  Cool |
|----------|:-------------:|------:|
| col 1 is |  left-aligned | $1600 |
| col 2 is |    centered   |   $12 |
| col 3 is | right-aligned |    $1 |

</center>

# Group Notes

(...)

Preview

---

If you use the ‘New Documentation’, it's not possible to center a table (since the table takes a full width of the column).

Preview

A simple method that everyone seems to have overlooked is to enclose the table within a div and use the align="center" property on it.

<div align="center">

| Tables   |      Are      |  Cool |
|----------|:-------------:|------:|
| col 1 is |  left-aligned | $1600 |
| col 2 is |    centered   |   $12 |
| col 3 is | right-aligned |    $1 |

</div>

Works just like <center> used to. No need to worry about <center> getting deprecated anymore. ;)

It is simple. As you know the "|-|" is used for indicate the table and ":" is used for indicate the text alignment. If |:-| entered that is a right aligned text column. If |-:| entered that is a left aligned text and if |:-:| entered that is a centre aligned.