I am completely new to Javascript/jquery world and need some help. Right now, I am writing one html page where I have to make 5 different Ajax calls to get the data to plot grap
you may combine all the functionality of the different ajax functions into 1 ajax function, or from 1 ajax function, call the other functions (they would be private/controller side in this case) and then return the result. Ajax calls do stall a bit, so minimizing them is the way to go.
you can also make the ajax functions asynchronous (which then would behave like normal functions), then you can render the graph at the end, after all the functions return their data.