SQL Server 2014 :: Sudden Increase In Table Size?

I save Table size and recs. no every day. and check it some days.

...
insert into @t
exec sp_msforeachtable 'exec sp_spaceused ''?'''
...

But Today I saw sudden increase size in a table. about 128 MB in a day. (Average Growth fro this table was 4 or 5 MB in a day)This growth was for Only 4222 Records. While for more number of records (about 7000) in yesterday we had only 2 MB GRowth!

This Table information (Now):

sp_spaceused 'Table1'

Result:

name ---Rows --reserved --data

Table1--1021319--460328 KB --283104 KBI Try to gess The reason. I copy These new records to another table.But The result was more strange : on new table the size of these record was : < 1 MB I copied All records to another table . The size was : 148 MB (while this is 283 MB in my real database)