Q.Avocados
When the avocados ripen there is a brownish spot about the size of a quarter near the bottom. All the avocados on the tree have the spot. When you cut into the avocados there is a soft brown spot which I cut out. The rest of the fruit is usually good to eat.
Some of the fruit have brown streaks left on the fruit after peeling and are stringy. Unfortunately there are none left and I did not think of taking pictures.
Is there anything I can do to get rid of this?

Certified GKH Gardening Expert
Yes. I would apply dolomitic lime. This could very well be a calcium deficiency. Apply dolomitic lime to the area to provide this for the tree. It would also help to provide wettable sulfur to the tree to prevent any bacterial or fungal infeciton. Otherwise, this is not harmful to you. Here is an article for more information on the care of this tree: https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-tree-growing.htm