Hugh I won't say what you "Should Do", that would be presumptuous of me, and There are guys that know a whole lot more than I do but I will say how "I" would do it based on what I know and understand if I wanted to go down the path you laid out.
Start with storing the data in words in the PLC
Process the data in the PLC
You said you wanted Avg and Min Max so the processed data is all you need, 3 values at what ever interval you want to record them.
Now you can use the Advanced HMI to Chart/Log just those 3 values. Since you only want the min max and avg you don't need to grab all the values you stored in the PLC to get those. If you post process in a DB you will need to grab all of it.
Now you can display the 3 different words ( For each of the 10 items you want) on the HMI, if you want, You can chart with out displaying it but it sounds like you wanted to see it in real time also. The word that has the MIN., The word that has the Max and The word that has the Average value. You can use a digital or analog Panel meter for that .
One project I am using this method for is storing wind speed
every second for 15 minutes using a first in first out then averaging the
900 words to get the Avg Wind Speed for the previous 15 minuets. It runs continuously so it is updating the avg every second. I show real time wind speed on the HMI and the Avg. I also Grab the Temp from a RTD connected to an IR module. I continually read the Temp on the HMI.
I chart the values of both avg wind speed and temp with a time interval in the HMI of 900,000 ( That's 15 minutes.) (15 x 60 ) / .001
Now I could put that data in a db but I am not interested it doing that. I am running 12 different set ups like that on one obsolete PLC 5 with varying file lengths. Several of them storing, averaging, and totaling data over a 6 month period but running continuously. That's a lot of Data and the PLC does it in less than a Second every scan.
So That is the simplest way to get and see the data you want using the same method.
For your project, you can set up a chart in the HMI, for the 3 values you want, 1 chart for each item with the 3 values. Depends on what you want.
Now you have the data you want - and you can use Open Office, Libre Office or Excell to view the spread sheets and create other charts .
You can also export the sheets to A database in one of those office programs. No SQL needed, Open Office and Libre Office both have database programs and they are open source. see
https://openoffice.orgThis way you have a feel for it and altogether it would not take much time at to get all that with the database in your office program.
That is not the best Database solution and I wouldn't use it if I wanted a long term solution but it will get you started and It is very easy to set up a simple db in those office programs but it is not a good long term solution for a DB doing what you want.
Now if you want to continue, with a robust DB then do as James suggested and set up A SQL, DB for it. You can set it up on the same machine you are developing AHMI on, And depending on where you are running the run-time of ADVHMI you can run it on that as well.
The great thing about MySql is it is super fast and you can run a lot of separate DBs on it on the same box and set up relational DBs so you can get data from more then one DB to analyze together, That also saves on the number of records needed because you can share a set of records across databases. You need to know a lot more about setting up a SQL DB then you do in an office Program DB though.
Have Fun!