If you're going to be doing several sheets, you should probably first
consider whether a mail merge might make sense (if you create a mail merge
data source, it can be edited and reused, not just for labels but for
letters, envelopes, directories, etc.). But a sheet of labels is just a
table and can be extended the same as any other by tabbing out of the last
cell or inserting rows. If the label cells are separated by spacer rows,
however, you'll need to copy the whole table and paste it on the next page,
as the spacer rows will not otherwise be reproduced.
