Adding Brands to Company Leads: Seeking Efficient Method for Handling 90-Row List

Hi there, This is the scenario. I have received a list of companies and the brands those companies have been advertising for. I have scraped the leads of those companies and now want to add the brands to the relevant leads of the company. I haven't found a good way doing it so far maybe someone has an idea on how to go about this. The list of companies is around 90 rows long and there may be a faster way to do it than manually creating the conditional formula for those 90 companies.