Mucocele: A mucocele is a common, benign lesion that can occur on the hard palate, often resulting from the obstruction of a minor salivary gland duct. The description of the lesion flaring with salty foods (which can stimulate salivary flow) and the ability to pop it with pressure (indicating a fluid-filled lesion) supports this diagnosis.

Ranula: Although more commonly found on the floor of the mouth, a ranula (a type of mucocele) could potentially occur on the hard palate and present similarly.
Mucous Retention Cyst: This is another type of lesion related to the obstruction of salivary gland ducts, which could present as a firm bump that fluctuates with salivary stimulation.
Traumatic Fibroma: A benign growth that can occur due to irritation or trauma, which might fit the description if the lesion is firm and has a history of trauma.

Squamous Cell Carcinoma: Although less likely given the description of the lesion being able to be "popped," it's crucial not to miss a potentially malignant lesion. Any persistent or changing lesion should be biopsied to rule out cancer.
Salivary Gland Tumor: While rare, tumors of the minor salivary glands on the hard palate can present as firm bumps. Some of these can be malignant, making biopsy essential for diagnosis.

Neurofibroma: A benign tumor of the nerve tissue, which could present as a firm bump but would be less likely to fluctuate with salivary stimulation.
Granular Cell Tumor: A rare, usually benign tumor that could occur on the hard palate, though it would not typically flare with salty foods or be easily popped.
Lymphangioma: A benign lesion composed of lymphatic vessels, which could present as a firm, fluctuant mass but is more commonly found in the tongue or floor of the mouth.