Theory:

I
 
Said the Table to the Chair,
"You can hardly be aware
How I suffer from the heat
And from chilblains on my feet.
If we took a little walk,
We might have a little talk;
Pray let us take the air,"
Said the Table to the Chair.
 
II
 
Said the Chair unto the Table,
"Now, you know we are not able:
How foolishly you talk,
When you know we cannot walk!"
Said the Table with a sigh,
"It can do no harm to try.
I've as many legs as you:
Why can't we walk on two?"
 
III
 
So they both went slowly down,
And walked about the town
With a cheerful bumpy sound
As they toddled round and round;
And everybody cried,
As they hastened to their side,
"See! the Table and the Chair
Have come out to take the air!"
 
IV
 
But in going down an alley,
To a castle in a valley,
They completely lost their way,
And wandered all the day;
Till, to see them safely back,
They paid a Ducky-quack,
And a Beetle, and a Mouse,
Who took them to their house.
 
V
 
Then they whispered to each other,
"O delightful little brother,
What a lovely walk we've taken!
Let us dine on beans and bacon."
So the Ducky and the leetle
Browny-Mousy and the Beetle
Dined, and danced upon their heads
Till they toddled to their beds.
 
~Edward Lear
About the Poem:
  
The poem belongs to the nonsense verse genre, where the poet talks about the conversation between a table and a chair. The table complains that its legs are getting hurt and proposes to go on a walk. They go on a walk and make merry but finally lose their way. They are helped by a Ducky-quack, a Beetle, and a Mouse, who later join in the fun with them.