Capacity of "Search Results" in "Manage Items"

Summary:

After I enter the task "Navigator -> Product Management -> Product Information Management -> Manage Items", and put some search criteria, items are showed in "Search Results".

Content (required):

Questions:

1. is there any limitation for amount of lines in the "Search Results"？
2. When there are many items being found, it seems more items are loaded when scroll down the "Search Results" and reach the end, instead of loading the whole searched item list in "Search Results". If I am going to "Edit Item Attributes in Spreadsheet", how to select all items in "Search Results" including the yet to be loaded ones?