Use Table as acceptable Vizier input

I have started resurrecting this Vizier feature. For now, you can do something like this:

    >>> from astroquery.vizier import Vizier
    >>> t = Vizier(catalog="VII/258/vv10").query_constraints(Vmag="6.0..10.0")[0]
    >>> t.pprint()
     Cl  nR      Name     n_RAJ2000  RAJ2000    DEJ2000  l_z   z     Sp n_Vmag  Vmag  B-V  r_z 
    --- --- ------------- --------- ---------- --------- --- ------ --- ------ ----- ----- ----
      Q     NPM1G+41.0135         O 06 55 10.0 +41 00 10      0.022  S?      R  9.37   nan  988
      A   *      NGC 3621         O 11 18 16.5 -32 48 51      0.002  S2         9.40   nan 2000
      A          NGC 4594         O 12 39 59.3 -11 37 23      0.002  S3         9.25  1.02 2456
    >>> for u in Vizier(catalog="II/246", columns=["_1","_q","_r","*"]).query_region(t["RAJ2000","DEJ2000"], radius="10s"):
    >>>     u.pprint()
     _1  _q   _r    RAJ2000    DEJ2000        _2MASS       Jmag  e_Jmag  Hmag  e_Hmag  Kmag  e_Kmag Qflg Rflg Bflg Cflg Xflg Aflg
    --- --- ------ ---------- ---------- ---------------- ------ ------ ------ ------ ------ ------ ---- ---- ---- ---- ---- ----
     -c   1  0.569 103.791864  41.002831 06551004+4100101 12.660  0.056 12.080  0.078 11.625  0.056  EEE  222  111  000    1    0
     _1  _q   _r    RAJ2000    DEJ2000        _2MASS       Jmag  e_Jmag  Hmag  e_Hmag  Kmag  e_Kmag Qflg Rflg Bflg Cflg Xflg Aflg
    --- --- ------ ---------- ---------- ---------------- ------ ------ ------ ------ ------ ------ ---- ---- ---- ---- ---- ----
     -c   3  6.785 189.995616 -11.624275 12395894-1137273 13.358  0.022 10.061    nan  9.821    nan  EUU  200  100  c00    2    0
     -c   3  1.996 189.997638 -11.622945 12395943-1137226 10.141  0.121  9.291  0.130  8.573  0.064  EEE  222  111  000    2    0

The first Vizier query gets the AGNs in the Veron & Cetty catalog, with Vmag in the range [6, 10].
The second query passes to 2MASS the coordinates of the previous result. Each returned table returns the matches within 10 arcsec.