On 2013–09–26 MANUEL GONZALEZ SUAREZ wrote:

> My questions are: how do the tables are centered on the page?

Horizontal centring is automatically applied when you make it float.

> Can you change the size of the tables?

The width keyword sets the width of the cells. There's also
option=stretch. Individual columns can be set with

  \setupTABLE [column] [2] [width=4cm]

> Can you include label and caption?

That's not a feature of tables, but of the float mechanism.

\starttext
  \startplacetable [title=Some table, reference=tab:foo]
    \bTABLE [width=broad]
      \bTR
        \bTD Alpha \eTD \bTD Beta  \eTD
      \eTR
      \bTR
        \bTD Gamma \eTD \bTD Delta \eTD
      \eTR
    \eTABLE
  \stopplacetable
\stoptext

Marco