Tea makes sense, G55, because it can be sweet when desired. (I can't stand sweet tea, but some people drink it that way!) And hobbits are very English in considering tea to be important. (I myself drink gallons of the stuff!)
HANG ON!
Is it hobbit meals? Six a day?
BREAKFAST
I am born the earliest
Considered by many the most important
I can be sweet when desired
Considered by many the most important meal of the day. Don't know if hobbits had breakfast cereal

, but they might put jam or marmalade on their toast, or treacle on their porridge (which is a cereal, I suppose).
SECOND BREAKFAST? MID-MORNING SNACK?
I am born Second
I am much the same as my elder brother
But I can be Salty if Desired
Now - Tolkien didn't say hobbits have second breakfast - it's just that Bilbo has one after he clears up after thirteen dwarves and one wizard.
But a mid-morning snack is perhaps more likely to be savoury than sweet.
ELEVENSES? DINNER?
Third Born am I
I am twice the one
I Am not as well known
The problem I have here is that it's the film that mentions this, not Tolkien. Although Elevenses are mentioned in stories about the traditionally English way of life. I first came across the term in the Paddington Bear books.
Twice the one sounds more like dinner, though.
DINNER
Fourth Born Am I
Many would use me to ease their labor
Yet two more brothers remain in this family.
I suppose hobbits - and people - break from work for dinner.
Hobbits have dinner twice a day when they can get it - although I don't know if they take them consecutively.
TEA
I am Fifth Born
I am the smallest of my brothers
I'm known sometimes for my biscuits
Sometimes have biscuits at tea (although I'd consider them more of a supper thing).
SUPPER
I am Sixth Born
I bring the family together.
I am last until my oldest brother is born again.
The last until breakfast, the oldest brother.