VariableTable: The `variable_table` exists to aid with computation, memory and network traffic optimization. It enables storing a variable once and reference it from multiple variables, including variables stored in the `variable_table` itself. For example, the same `this` object, which may appear at many levels of the stack, can have all of its data stored once in this table. The stack frame variables then would hold only a reference to it. The variable `var_table_index` field is an index into this repeated field. The stored objects are nameless and get their name from the referencing variable. The effective variable is a merge of the referencing variable and the referenced variable.