A .sdf file can contain multiple structures. When imported into MS (Materials Studio), the structures are collected into a single “trajectory” (.xtd) file. The attached example .sdf file (sample.sdf) appears similar to the following screenshot when imported into MS:

The trajectory document, sample.xtd, contains all the 10 structures from the sample.sdf file. One may separate the structures into individual cells in a study table, using the “Insert From File” utility to insert sample.xtd, resulting in a study table similar to the following: