Let's add some data to your table.
Create a new script called myData and add the following code to your script:
tables.myTable.insertRow();
tables.myTable.A.value="A1";
tables.myTable.B.value="B1";
tables.myTable.C.value="C1";
tables.myTable.insertRow();
tables.myTable.A.value="A2";
tables.myTable.B.value="B2";
tables.myTable.C.value="C2";
tables.myTable.insertRow();
tables.myTable.A.value="A3";
tables.myTable.B.value="B3";
tables.myTable.C.value="C3";
This code will add and populate three new rows in your table.