Yes, the sizes of the defect fields (where aplicable) are specified in the Fields table. You can try modifying the size of the Name field for defects, but it may change the way it looks on the window/page (I believe fields of size over 100 will be rendered as multi-line).
Do note, however, that modifying the sizes of the columns in existing tables is not recommended as it may break other things in the application, and in the future may cause problems upgrading.
Dan Suceava
http://www.axosoft.com