This formula "glues together" the pieces of text that appear in B4, C4, and D4 using the ampersand (&) which is the concatenation operator in Excel.
In between each piece of text, the CHAR function appears with the character code 10. The character code for a line break in Excel varies depending on the platform. On Windows, the code is 10 and on a Mac it's 13.
The result of the concatenation is text with line breaks:
1301 Robinson Court¬
Saginaw, MI 48607
Note: make sure you have Wrap Text enabled on cells that contain line breaks.