Adding monthly data to Power BI via Excel

Hello,

I have added data from June to my Power BI, and am able to do visualisations from it, so all fine. 

Now, I need to add data from July, and future months going forward when they are available at the end of the month. 

I added July by just adding another table. The issue is, I don't seem to be able to do any visualisations for change over time, so bar charts with the amount of a category for June, and then July afterwards. It seems to be because they are two separate tables of data in Power BI.

Is there a better way I can add more data each month? Or am I doing the visualisations wrong?

Also, the data in question is not just June: 1, 2, 3 and July: 1, 2, 3. They are identical tables with 9 columns across and over 100 rows, and obviously different data filled in under these same columns etc.