What is the meaning of 附件 here? What do they mean by '铅笔附件‘ and '配套件‘？ 

'铅笔附件‘ maybe: the box that the pencils come in? Or the lead in the pencil, in case it contains harmful chemicals?

宁波检验检疫人员提醒文具出口企业，要重视铅笔附件和配套件的安全性能。
It just means that some widgets or accessories for pencil. "附近" and "配套件" make a general reference. More time they won't be indicate what certain things they are. So don't think too much.