If "TV set of 42 inches..." is the text in a single field, I don't see how it is possible for you to only get the first word.
Invoicing system usually are based on this set of tables and relationships:
The match fields for Line items to ProductsAndOrServices should be:
LineItems::ProductID = ProductsAndOrServices::ProductID
For fields such where you want to copy the data from ProductsAndOrServices into a corresponding field in LineItems, you'd go to Manage | Database | Fields, find the field in the LineItems table and double click it to open field options. There, you click the auto enter tab and select the looked up value option. In that dialog you can select first the ProductsAndOrServices table occurrence and then you select the field in that table that contains the data you want to copy. When the Data in PRoductID is modified or entered, the complete contents of this specified field will be copied over into the field in LineItems.
In the case of the product description field as you describe in your initial post, make sure both the field in Products and the field in LineItems are of type text.
Thank you. It was my mistake, never the less, thank you. I was actually referring to a hidden field on the table that has almost the same name, so, the outcome was it was expected, but not what I was expecting, and was killing me.