that’s not unusual for aliases created through Finder. If you’re concerned about the amount of space that the Finder alias uses, one alternative would be to create a symbolic link alias instead via the command line in a Terminal window. For example, to create a symbolic link alias on your Desktop for a text file in the Documents folder, you could run the following command in Terminal:
ln -s ~/Documents/sample.txt ~/Desktop/"sample.txt alias"
The symbolic link alias only uses enough space to hold the name of the file being pointed to.