Hi Bruce,
Yes - For a use-case like that, when you plan to have several thousand rows of data, the best way is to go for our server-side processing feature.
You can learn more about how it works here;

And here you can see our example of a very large SQL Query based table ( a couple million rows) and see how it loads.

In short, it uses Admin-Ajax calls to only load one table page at a time and you can combine this with our custom number of rows per Page in table's display settings.
Set it as low as possible to improve the loading speed.

Basically, just avoid having the "ALL" option there, so a user can't set to load all rows on front-end.
Other than that, we recommend allowing any options from 5 rows up to 100 rows and there should be no performance issues, you can test that and see how it works, depending on your Hosting server performance, setup, etc.
( if you wish to let the front-end user change the current presented number of rows per page)


2. I advise against using a PHP array in this scenario, but it depends on how many rows in total are planned per table.
If you won't have more than 5, 6 thousand rows - Then you can use our Cache feature for improved performance.

But if it goes more than that, then the server-side ( SQL based) tables are the way to go.



3. Also, we need to graph the data in addition to providing it in tables. Assuming the data are of an appropriate type (e.g., appropriate x and y values are available) can a table of dynamically generated data be used to generate a graph?

Absolutely - As long as you follow some basic rules/limitations of the chart engines, there should be no issues, you can make a chart from our tables.

For example, each chart can only have one String or Date column type included and the rest must be numeric columns for the series.

- You can also include our Formula  columns in a chart.

- We currently can't include the calculation functions  in charts.

You can check out all the available chart engines and examples of wpDataCharts documentation here .

And i just wanted to point out that you can try wpDataTables before purchasing

 on our sandbox Demo sites ( you can find links for the main plugin Demo,  

as well as add-on Demos, in my signature),

and there is a 15-day money-back guarantee period, 

so if you purchase the plugin, you can safely fully test it out, and if it doesn't fit your needs you can request and receive a refund in that period. ( same goes for all plugins and add-ons)

Let me know if you have any additional questions.