Chris begins by saying that he's going to use all the information that Hannah (Ms. Graff) has presented as a starting point.

A “starting point” is the place where someone begins something, or the information that one uses to begin something.

If you want to lose 20 pounds (you want to go on a diet), your starting point may be how much you weigh right now.

Chris's starting point is Ms. Graff's, or Hannah's, information, meaning that he's going to continue from where her information ended.

Chris says that his product development team (the people who work on improving and making new products for the company) has been trying to enhance (enhance), or improve, the product to include more of the features, or product characteristics, that customers are looking for.

He says that his specific proposals were described in detail in a memo.

A “proposal” (proposal) is one's suggestion or idea about what, how, and when something should be done.

For example, when a nonprofit organization (a hospital or a school, for example) asks for money from businesses, it usually has to write a proposal to explain how the money will be spent.

A “proposal” is usually a written plan about what you want to do - what you are suggesting.
Chris's proposal is about how the product should be improved, or enhanced.

A “memo” (memo), which is short for “memorandum” (memorandum), is a short written message in a company or a business, usually to share information in an office.

A memo is usually written on a piece of paper.

The top of a memo usually has at least four lines, with the name of the person who wrote it, the name of the person or people it was written for (the people who should read the memo), the date, and the subject of the memo (the topic of the memo).

Chris's memo was about the team's proposals, or ideas for improving the product.

He said that the memo circulated last week.