Large dictionary warning
This warning is displayed if size of compression dictionary in extracted or tested RAR archive exceeds the limit specified in Settings/Compression. You can select "Extract" to continue or "Cancel" to stop further archive processing.
Extraction and archive test commands allocate the amount of memory slightly larger than dictionary size. If dictionary size is smaller than physically available memory size, you can also set "Always extract files with dictionary not exceeding" option and specify the new limit to unpack without this prompt. It also can be changed in WinRAR settings.
If dictionary size is equal to or larger than physically available memory size, the option to change the limit isn't available. It is not recommended to start extraction in this case, because it can be extremely slow, exhaust the available memory and make the entire system unresponsive.