Marina;
There are a few things you can do to minimze the seediness in eggplant. First, pick young small eggplant to work with. The trend in mass produced vegetables is large sized. This is unfortunate as most, if not all, vegetables are actually at their best when picked young and small. Also, look for different variesties of eggplant. The Asian varieties, characterized by the longer, thinner banana type shape, are usually far less seedy than their Western counterparts.
If you must select from the mammoth eggplants in the local super-mega mart, look for eggplants that are very heavy feeling for their size. The seeds have not had time to fully develop in these eggplants which makes them infinitely more palatable.