Do we gonna loose the already existing data in production?

Hello,

I have a custom table (say, Z_TBL) w/ 63 fields, these fields are like below,

WERKS_1
WERKS_2
WERKS_3 like that upto WERKS_30. All these 30 fields of Plant has been assigned w/ standard SAP WERKS_D data element

Same case w/ MATNR fields, I mean,

MATNR_1
MATNR_2
MATNR_3 like that upto MATNR_30; All these 30 fields of MATNR has been assigned w/ standard SAP MATNR data element, well.

Then, additional 3 fields, like PO_NUMBER, START_DATE and END_DATE,

Currently, in production we have around 1000 records in Z_TBL_1.

Now, my requiremnt is: Users want to see Plant & its description in one field together w/ a hyphen seperator and same case w/ MATNR,
example for plant,

Today the data is as 1234
To-be 1234 - US CA Plant

Hence I need to increase the each single field length, say if its a MATNR, currently its length is 18 in my Z_TBL, I need to increase it to 58

Pls. let me know (fyi...Z_TBL doesn' hv a TMG)

1) If I increase the each single field length in Z_TBL and transport it to PRD, do we loose the currently existing data of 1000 recs in production?

2) If we looses, then what are the alternatives?

3) Before & after increasing the length, any prerequisit steps or precaustions I need to consider? I knew that I need to do SE14

4) Any better approach to achive my requirement?

Thank you