Question: Can Table Values Be Modified in maple tables()

The example worksheet uses table to determine the covering relations in a POSET. This is old (Maple 11 and earlier code) that I have been trying to update into a package to explore calculations in an algebraic structure.  The example procedure seems to work well, but because of problems with similar procedures elsewhere, I have some concerns about the validity of using tables in this fashion. Specifically, this procedure initializes a table, then proceeds to modify the table entries, and then reformats the sequences into sets.  I have not been able to find documentation for modifying entries in tables after they have been defined. The documentation for tables only covers adding entries, removing entries, but not modifying entries.

Is modifying tables as my  procedure does an undocumented feature?

In addition, the documentation does not explain how to clear a table. It only describes how to clear a table entry. Older code sometimes purported to clear a table by assigning its name (with uneval quotes) to itself, but this does not seem to work.

exampletableoperations.mw