First of all, the data has to be in a format that will transfer properly. This may require a lot "clean up" in the Excel file. You would need to remove any worksheet headings, blank rows and columns and make sure the first row contains unique column headings without being wrapped or no special symbols. The data should be in rows without totals or subtotal rows. Any formulas would import in as values.
Your Word document must be set up as a mail merge document, using the column headings as your field codes. There are excellent tutorials at Microsoft on using Word's Mail Merge features:
In addition, ITS will host a Word Mail Merge session on Wednesday from 10-11:30 a.m. in which you'll learn how to merge Excel data into Word for labels, envelopes, letters and tables. Register online.