The attack on Claudius’ kingdom by Fortinbras Jr was diverted to an attack on Poland.
The attack on Claudius by Hamlet Jr was diverted to an attack on Polonius.
Shakespeare reinforced that parallel with word-play, starting with the obvious “Poland”/”Polonius”.
Other examples:
Polonius
Behind the arras I'll CONVEY myself,
....
Fortinbras
Go, captain, from me greet the Danish king;
Tell him that, by his licence, Fortinbras
Craves the CONVEYance of a promised march
Over his kingdom.
...
Hamlet (looking in a grave)
The very CONVEYances of his lands will hardly lie in this box
================
Hamlet
How now! a rat? Dead, for a DUCAT, dead!
....
Captain
Truly to speak, and with no addition,
We go to gain a little patch of ground
That hath in it no profit but the name.
To pay five DUCATS, five, I would not FARM it;
Nor will it yield to Norway or the Pole
A ranker rate, should it be sold in fee.
.....
Polonius
Be you and I behind an arras then;
Mark the encounter: if he love her not
And be not from his reason fall'n thereon,
Let me be no assistant for a state,
But keep a FARM and carters.
==============
Polonius announced the ambassadors from Norway who would tell Claudius that Fortinbras’ attack had been shifted to Poland:
....
Polonius
Give first admittance to the ambassadors;
MY news shall be the FRUIT TO THAT GREAT FEAST. [the end or dessert]
....
After the ambassadors delivered their news:
Polonius
This business is WELL ENDED.
......
After Hamlet’s attempt to attack Claudius caused Polonius’ untimely end:
Ophelia
...when my father died: they say he made a GOOD END,
.....
Claudius
Now, Hamlet, where's Polonius?
Hamlet
At supper.
Claudius
At supper! where?
Hamlet
Not where he eats, but where HE IS EATEN: a certain convocation of politic worms are e'en at him. Your worm is your only emperor for diet: we fat all creatures else to fat us, and we fat ourselves for maggots: your fat king and your lean beggar is but variable service, two dishes, but to one table: that's THE END.
======================
There was another foreshadowing of Polonius as dessert:
Hamlet
....AFTER YOUR DEATH you were better have a bad epitaph than their ill report while you live.
Polonius
My lord, I will use them according to their DESERT.
Hamlet
God's bodykins, man, much better: use every man after his DESERT, and who should 'scape whipping?
I wasn’t sure that “dessert” was an English word back then, until I found this:
http://www.etymonline.com/index.php?term=dessert
dessert
1600, from M.Fr. dessert (1539) "last course," lit. "removal of what has been served," from desservir "clear the table," lit. "un-serve," from des- "remove, undo" + O.Fr. servir "to serve."
======
There's also a related motif that brings Polonius to the table:
Polonius
Your bait of falsehood takes this carp of truth
......
Hamlet
...you are a fishmonger.
Polonius
Not I, my lord.
Hamlet
Then I would you were so honest a man
.....
Hamlet
Not where he eats, but where he is eaten: a certain
convocation of politic worms are e'en at him. Your
worm is your only emperor for diet: we fat all
creatures else to fat us, and we fat ourselves for
maggots: your fat king and your lean beggar is but
variable service, two dishes, but to one table:
that's the end
.....
A man may fish with the worm that hath eat of a
king, and eat of the fish that hath fed of that worm
So maybe the fruit of the great feast was an apple with a worm in it
(or worse, half a worm).