If you have to have the addresses in a 2-column table with gridlines, then while making the field merge, use soft line breaks between lines of data belonging to the same contact but use hard line breaks at the end so that there is a hard line break between data belonging to different contacts. You insert soft line break by pressing Shift +Enter, as against just Enter which inserts hard line break. If you want to see which kind of break is being inserted press Ctrl+Shift+*, the hidden formatting marks will be revealed. A soft line break looks like a right angled arrow, and hard break is paragraph mark.
e.g. First Name Last Name (soft line break)
Address1 (soft line break)
Phone (Hard Line break)
After doing the mail merge, when all the addresses are seen on the document, then select all the text by pressig Ctrl+A, go to Insert Menu, choose "Convert text to table" under Table Menu, and in the dialog box, choose 2 in the Number of Columns field, and "Paragraphs" under "Separate Text At". You will see that Word creates a two column table, with each contact's address in individual cells of the table.
Originally Posted by Venky62
In Word 2010, the catalogue merge is called Directory. You will find this when you click on the start mail merge button under the Mailings menu.
After you have merged the address fields with your document, go to page layout menu and click on columns button. From the drop down list, choose 2 colums. Your merged addresses will be arranged in 2 columns. You can then fine tune the columns and the address fields using the ruler etc.