While hash tables are versatile data structures with numerous advantages, there are certain scenarios or problems for which they may not be the most suitable choice. Here are some examples:

1. Ordered Data: Hash tables do not inherently maintain any particular order among the stored elements. If the order of the data is significant and needs to be preserved, a hash table may not be the best option.

2. Range Queries: Hash tables excel at retrieving individual elements by their keys. However, they are not well-suited for range queries, where you need to retrieve all elements within a given range of keys. Range queries typically require traversal of the data in a specific order, which is not supported by hash tables.

3. Prefix Searching: Hash tables are not designed for efficient prefix searching. If you need to perform prefix-based searches or find keys that have a common prefix, specialized data structures like prefix tree would be more appropriate.

4. Memory Constraints: Hash tables require a certain amount of memory to store the hash table itself and handle collisions. If memory is limited or needs to be conserved, hash tables may not be the best choice.