By saying he will put on a show, Walter means he will boldly confront and challenge Mr. Lindner's prejudice and discrimination. He recognizes that Mr. Linder's visit is an attempt to intimidate and dissuade them from moving in, and he is ready to stand up to him.
Walter's metaphorical show implies that he will demonstrate his unyielding spirit and unshakeable resolve in the pursuit of their dreams and equality. He is determined not to cower in the face of pressure and intends to make a powerful statement about the dignity and rights of his family and the African American community.
Ultimately, Walter's metaphorical reference to "putting on a show" encapsulates his newfound strength, courage, and determination to navigate the challenges and inequalities prevalent in their society.