How to find the highest value in Number Value?

Okay, it's a quick explaination.

I will have a value which represents the highest value at the time, I call it "HighestNow".

I will run over the table to check the highest value, take this as an example:

local TableOfValues = {2,5,3}--According to your question.
local function ReturnBiggest(Table){
	local HighestNow = 0
	local ReturnValue = nil
	for key,value in pairs(Table) do--Run through to whole table.
		if value > HighestNow then
			HighestNow = value
			ReturnValue = value--Assume the highest value is this because we don't know.
		elseif value == HighestNow then
			print('There are two values same, just a warning.')
		end
	end
	--We ran the table throughout, now return the value!
	return ReturnValue
}
local rt = ReturnBiggest(TableOfValues)
print(rt)-- Should be 5

Edit: You want it to work, here it is:

local TableOfValueObjects={NumberValueObject1,NumberValueObject2,NumberValueObject3}--According to your situation.
local function ReturnBiggestFromNumberValue(Table){
	local HighestNow = 0
	local ReturnValue = nil
	for key,obj in pairs(Table) do--Run through to whole table.
		if obj.value > HighestNow then
			HighestNow = obj.value
			ReturnValue = obj--Assume the highest value is this because we don't know.
		elseif obj.value == HighestNow then
			print('There are two values same, just a warning.')
		end
	end
	--We ran the table throughout, now return the value!
	return ReturnValue
}
local rt = ReturnBiggestFromNumberValue(TableOfValueObjects)
print(rt)-- Should be some object.