ocaml getting syntax error

I am getting syntax error on the line "module usingTable : TABLE =" and the word usingTable is highlighted red when I try to run this code in oCaml. I want to create table of the format as in the execution example bellow. What is wrong with it? The environment I am using is this one https://try.ocamlpro.com/fun-demo/tryocaml_index.html#path%3Dtries as I couldn't understand how to use cygwin or oCaml Bash in windows.

module type TABLE = 
sig
  type table 
  val emptyTable : table
  val printTable : table -> string
  val create_table : string * string list * (string list) list -> table  
end;;

module usingTable : TABLE =
struct
  let emptyTable = ()
  let table = (string * (string * string list) list) 

  let rec printTable aTable = match aTable with
      ()->""
    | (title, [data]) -> "\n"^title^"\n\n"^printTable(data)
    | [(col,cont)::t] -> col^"   "^printTable([t]) 
end;;

let atable = usingTable.emptyTable;;
let atable = ("Student", [("Id", ["2";"4";"7";"9"]);
                          ("Name", ["Jim";"Linnea";"Steve";"Hannah"]);
                          ("Gender",["Male";"Female";"Male";"Female"]);
                          ("Course",["Geography";"Economics";"Informatics";"Geography"])
                         ]);; 
print_string (usingTable.printTable atable) ;;

As suggested in my comment, you may want to take a look at some additional references before focusing again on this code example (which contained not only syntax errors but also type errors).

For example, I'd suggest the following links:

• the official OCaml documentation, in particular you may first look at:
  • https://ocaml.org/docs/values-and-functions
  • https://ocaml.org/docs/basic-data-types
  • https://ocaml.org/docs/tour-of-ocaml
• the so-called 99 problems in OCaml (a collection of quite standard exercises);
• the Real World OCaml (an online book providing a comprehensive insight on OCaml);
• the official OCaml reference manual;
• and it might also be useful to have by hand the URL of the doc of the Stdlib module (i.e., the module of the standard library that is always loaded by default);
• finally the OCaml programming guidelines page may be of some help if you are looking for a compilation of "standard style recommendations / best practices".