The text &[Tab] in one of the custom header sections (left, centre or right) will print the worksheet name in that header section. This will result in "Graph" being printed in the header, as "Graph" is the name of the Worksheet.
The custom header and footer commands are limited to what you can enter using the row of icons, (or directly entered text). You can't use the custom header to include rows of data from another worksheet.
If you want to print your Graph after the 7 rows on the header worksheet, you will need to copy the Graph into the right place in the Header worksheet.
You mention that the header repeats several times. Does this mean that there are several versions of the Graph, each using different data.
Just another thought - did the previous owner of this workbook use a macro to print it. Try clicking Alt+f11 (the Alt key and function key #11 pressed together). This opens the Visual Basic window. Look at Project Explorer on the left (if not visible, go to the VB Menu, select View and click Project Explorer). Look for VBAProject(<MyWorkbook.xls>).
Then double click the various elements underneath - each worksheet name, "This Workbook" and if present, any modules (e.g. Module1). If any visual basic code shows up in the large window on the right, you could copy it and post it for someone to review. If posting code please place it between the <pre> and </pre> tags (at the top of the reply box) - they help keep the formatting especially for code.