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.

-- t is a table with all your numberValues 
local function sortVals(t)
    local largest = -math.huge
    for _, numberValue in pairs(t) do
        largest = math.max(largest, numberValue.Value)
    end
    return largest
end

probably the easiest way, considering you only want one value.

and much shorter than the solutions before..