I've seen in another thread that an option is to create a table for every item and add/remove tables when i need add or remove some item... but in my case, i could ever need a hundred of items... that would mean a hundred of tables created.
I confirm that's the way to go

When a table is added, i can see that is done a request to control.html.. if i have 100 tables, would be done 100 requests?
no, you will get less control requests as such requests will be batched together. How many batches will be produced for 100 tables depends on an heuristic algorithm on the client and on the <request_limit> element of the Lightstreamer server configuration.

Please note that control.html requests are obsolete and are used by the client library only as a backup. So either you're using an old client library or are in a strange scenario.
In case you're using an old library please upgrade it if possible.


On the other hand, could I use setCommandLogic to achive the behaviour i want?
to enable the command logic you need first an adapter that produces a COMMAND item, that's a completely different scenario; the "row" to be shown must be decided on the server through such COMMAND item. Please check out the desctiption of the COMMAND mode in the General Concepts.pdf file you can find under the DOCS-SDKs folder of Lightstreamer distribution to check if it can fit your needs. Let me know if you need clarifications on this.