When someone says they have "bigger fish to fry," they mean they have more important or pressing matters to attend to. Some other common phrases with a similar meaning include "more pressing concerns," "more important things to do," or "higher priorities to tackle." Additionally, someone might say they have "larger issues at hand" or "greater challenges to face." Regardless of the phrasing, the speaker is conveying that the task at hand is of lesser significance than other matters they must address. This phrase is often used to indicate that the subject being discussed is not worth the speaker's time or attention.