PPC Keyword Report – Best way to utilize the data?

I am going through the PPC keywords report and basically 50% of the clicks do not convert into a sale. The percentage of PPC costs for keywords than do not convert is also very close to 50% of total ad spend.

Many of the keywords that do not convert seem relevant to the products for sale. My report is based on 90 days of data.

I also see a huge amount of ASIN related “customer search terms” but many if not most are my own products. It’s like its advertising my products on my other products. Sometimes on competitors products and sometimes on totally non related products.

What would you do to help cut back on wasted spend? We spend around 20k a month.