Shortcut function to assign a Opal table to a tibble in the R server-side session
and then retrieve it into the R client-side session. Requires to have the permission to
see the individual values of the table and to perform R assignments.
Table name from which the tibble should be extracted.
variables
List of variable names or Javascript expression that selects the variables of a table (ignored if value does not refere to a table). See javascript documentation: http://wiki.obiba.org/display/OPALDOC/Variable+Methods