Say I have two tables (Apples and Oranges) with the same columns and just a different table name. Would there be any advantages/disadvantages to turning this into one table
The advantage would be normalization. Your tables would then be in 2NF (second normal form).
Your fruit type would be a foreign key to a table with those fruits like so:
CREATE TABLE fruit_type (type varchar(15))
CREATE TABLE fruits (id int, weight int, variety varchar(255), type varchar(15))