The phrase "to attach any chart" means to include or add a chart as a separate file or document along with the main information or context. Full definition
In addition to the information provided in this article, we are also attaching a chart below to serve as a quick reference guide for parents. (familysleepinstitute.com)
The Republican Caucus strongly opposes this request which clearly argues against the beliefs of 83 percent of the public, as expressed in last year's referendum (see attached chart showing overwhelming support for downsizing). (www2.erie.gov)
For example, one can see the strong relationship between the price of oil (inverted in attached chart) when plotted against the dollar index. (business.financialpost.com)