Hi Victor,
The Html content feature is not a development tool it is just a content feature. There is no easy way to make it load data from your custom table, you would typically implement a custom feature to do something like that.
You can use javascript inside the html content feature, so in theory if you implemented a custom service ie a .ashx handler that returns your data formatted in json format you could write some javascript to call that service and populate an html table with it. But in both these scenarios custom development is required and which approach to use would be determined by your own skill set and preferences.
You can study the code of existing features to learn how to develop your own features and we have lots of developer documentation and a series of videos that can walk you through developing a custom feature.
Hope that helps,
Joe